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301 Posts
Discussion Starter · #1 ·
ok, i know everyone probably hates to discuss emissoins but... I just called the DMV (Connecticut) and they told me that for 96 and newer vehicles, the only thing that is done at the emission station is an OBD II test. I had just asumed that we had the full sniffer, OBD and visual, but they said ONLY obd test.
Can someone explain to me if this is a good thing or not [:(] ? I have an excall II so is there a potental to run straight headers back or turbo and just have to reflash and clear the codes before an emissions test or is the obd test more involved than that. any experts in the crowd?

13,065 Posts
If the Xcal 2 can completely clear the codes then you're cool running whatever. If you do it the "old school" way, unplugging the battery then booking it over to the inspection station, it won't fly. Because the OBD scanner will look to make sure "all good" and if it's been reset, the codes will come back as "not sure, need to run that self-test again"

In which case they will make you wait a few minutes til the system checks itself (and throws a code again) or have you come back, or something. If the Xcal clears it so that the system checks itself and says "ok, all systems go" then you'll be fine. And I suspect it Does work that way.

But otherwise, usually "just OBD" means that and nothing more, no visual looking for cats or anything. Plug in the tool, no codes, you're cool. Sometimes they check the horn or lights too, to make sure such "safety" items don't need replacing.

RI's system is similar to the "new" CT one, and it only takes like 10 min tops for a RI car (96+) to get inspected.

301 Posts
Discussion Starter · #3 ·
The only emissions significant codes would have to do with a malfunctioning cat correct? So if the second o2 sensor was disabled then it would, in theory, never throw a code right? do you think that when they check the OBD system, they can tell if there is an aftermarket program running? This just seems to easy to run headers with an excal II and just drive up and get tested and pass. [8]

301 Posts
Discussion Starter · #4 ·
The more I look around the more I see things like, the test stations can tell if a code has been thrown (and cleared), and some sites say they check things like cat temps and and other such info that wouldent be logged on a ECU running a car with one or no cats... anyone have first had experience here? or dose anyone have a full list of things tested in an obd inspection?

301 Posts
Discussion Starter · #5 ·
ok, this is long, but it answerd my question and maby it will help someone else too. I found out about the readiness monitors, which there are a few of, and they all must be set after either unplugging the battery or clearing any codes because if they arnt all set, then there will be a code " p1000 " stuck in the ecu memory which cannot be cleared in any other way besides these drive cycles. so if you just clear your codes and go to an emissions station, then they will hook up and tell you that you need to go drive around and come back another day. So im still unsure of how someone could get by with a header without replacing it for emissions... but anyhow, heres what i found.

The P1000 is a systems readiness check. Certain conditions need to occur in order to verify that certain components like the EGR, evaporative systems, catalytic converts, and other systems are working.

The quickest way to clear the P1000 is to follow the following drive-cycle as stated by Ford. I have done the drive cycle enough times to where I can now do the drive cycle in about 25 minutes.

Ford Motor Company Driving Cycle

Description of OBDII Drive Cycle
The following procedure is designed to execute and complete the OBDII monitors and to clear the Ford P1000, I/M readiness code. To complete a specific monitor for repair verification, follow steps 1 through 4, then continue with the step described by the appropriate monitor found under the "OBDII Monitor Exercised" column. When the ambient air temperature is outside 4.4 to 37.8°C (40 to 100° F), or the altitude is above 2438 meters (8000 feet), the EVAP monitor will not run. If the P1000 code must be cleared in these conditions, the PCM must detect them once (twice on some applications) before the EVAP monitor can be "bypassed" and the P1000 cleared. The Evap "bypassing" procedure is described in the following drive cycle.

The OBDII Drive Cycle will be performed using a scan tool. Consult the instruction manual for each described function. NOTE: A detailed description of a Powertrain Control Module (PCM) Reset is found in this section, refer to the table of contents.

Drive Cycle Recommendations:

1. Most OBDII monitors will complete more readily using a "steady foot" driving style during cruise or acceleration modes. Operating the throttle in a "smooth" fashion will minimize the time required for monitor completion.
2. Fuel tank level should be between 1/2 and 3/4 fill with 3/4 fill being the most desirable.
3. The Evaporative Monitor can only operate during the first 30 minutes of engine operation. When executing the procedure for this monitor, stay in part throttle mode and drive in a smooth fashion to minimize "fuel slosh".


For best results, follow each of the following steps as accurately as possible:

OBDII Monitor

Drive Cycle Procedure
Purpose of
Drive Cycle Procedure
Drive Cycle

1. Install scan tool. Turn key on with the engine off. Cycle key off, then on. Select appropriate Vehicle & Engine qualifier. Clear all DTC's/ Perform a PCM Reset. Bypasses engine soak timer. Resets OBDII Monitor status.

2. Begin to monitor the following PIDs: ECT, EVAPDC, FLI (if available) and TP MODE.
Start vehicle WITHOUT returning to Key Off.

3. Idle vehicle for 15 seconds. Drive at 64 Km/h (40 MPH) until ECT is at least 76.7°C (170° F).
Prep for Monitor Entry

4. Is IAT within 4.4 to 37.8°C (40 to 100° F)? If Not, complete the following steps but, note that step 14 will be required to "bypass " the Evap monitor and clear the P1000. Engine warm-up and provide IAT input to the PCM.

5. Cruise at 64 Km/h (40 MPH) for up to 4 minutes. Executes the HEGO monitor.

6. Cruise at 72 to 104 Km/h (45 to 65 MPH) for 10 minutes (avoid sharp turns and hills) Note, to initiate the monitor: TP MODE should =PT, EVAPDC must be >75%, and FLI must be between 15 and 85% Executes the EVAP Monitor (If IAT is within 4.4 to 37.8° (40 to 100°F))

7. Drive in stop and go traffic conditions. Include five different constant cruise speeds, ranging from 40 to 72 Km/h (25 to 45 MPH) over a 10 minute period. Executes the Catalyst Monitor.

8. From a stop, accelerate to 72 Km/h (45 MPH) at 1/2 to 3/4 throttle. Repeat 3 times. Executes the EGR Monitor.
SEC AIR/CCM (Engine)

9. Bring the vehicle to a stop. Idle with transmission in drive (neutral for M/T) for 2 minutes. Executes the ISC portion of the CCM.
CCM (Trans)

10. For M/T, accelerate from 0 to 80 Km/h (o to 50 MPH), continue to step 11. For A/T, from a stop and in overdrive, moderately accelerate to 80 Km/h (50 MPH) and cruise for at least 15 seconds. Stop vehicle and repeat without overdrive to 64 Km/h (40 MPH) cruising for at least 30 seconds. While at 64 Km/h (40 MPH) , activate overdrive and accelerate to 80 Km/h (50 MPH) and cruise for at least 15 seconds. Stop for at least 20 seconds and repeat step 10 five times. Executes the transmission portion of the CCM.
Misfire & Fuel Monitors

11. From a stop, accelerate to 104 Km/h (65 MPH). Decelerate at closed throttle until 64 Km/h (40 MPH) (no brakes). Repeat this 3 times. Allows learning for the misfire monitor.
Readiness Check

12. Access the ON-Board System Readiness (OBDII monitor status) function on the scan tool. Determine whether all non-continuous monitors have completed. If not, go to step 13. Determines if any monitor has not completed.
Pending Code Check and Evap Monitor "Bypass" Check

13. With the scan tool, check for pending codes. Conduct normal repair procedures for any pending code concern. Otherwise, rerun any incomplete monitor.
Note: if the EVAP monitor is not complete AND IAT was out of the 4.4 to 37.8° C (40 to 100° F) temperature range in step #4, or the altitude is over 2438 m. (8000 ft.), the Evap "bypass" procedure must be followed.
Proceed to step 14. Determines if a pending code is preventing the clearing of P1000.
Evap Monitor "Bypass"

14. Park vehicle for a minimum of 8 hours. Repeat steps 2 through 12. DO NOT REPEAT STEP 1. Allow the "bypass" counter to increment to two.

314 Posts
Having just wasted a few days sitting through the classes..

OBD II inspection can pretty much be defeated by a tuner. ANY SES light will cause an immediate failure. For the state of Texas, you can have up to 3 systems "Not Ready", meaning the test cycle for that system isn't complete. If you have a downstream cat code, you can get away with unplugging your battery. That test cycle takes FOREVER to complete on a Ford. Just make sure you get about 10 miles or so of mixed driving on your way to the inspection.

With the OBD inspection, you are still subject to safety and visual inspection. If they bother to look, they're going to look for cats and mufflers. You ARE required to have all the emissions systems your car came with stock or an equivalent system. But how many people are going to know all the systems that came on every car? So usually they just look for a cat somewhere.

696 Posts
Well, in Illinois, it's similar. Had my '96 eclipse in for the OBD II test 2 years ago. Was leaking oil from the head and blue smoke was visable out the exhaust. The tech laughed and said you really expect to pass with that? I said sure, why not. He checked the chip, and it was clear. No sensors going off, had AEM CAI, no cat, and aftermarket can. No visual was done, even with the smoke. However, I had a '91 amigo that had a code for something not even important and they said since a code came up period, I'd have to get it fixed and come back.


13,065 Posts
Ok, my non-eloquent post was trying to describe the p1000, I just couldn't remember what it was called.

But tuners like XCal won't give a P1000, the ECU will see all its parameters as "ready". My mechanic/inspector takes a look under the car, not under the hood, so if you replace the header but have a catback exhaust on a Duratec, you pass the visual. And with a tuner, you pass the OBD too.

301 Posts
Discussion Starter · #9 ·
sweet, so if an excall dosent throw a p1000 than you can do whatever you want basically. I called the CT DMV and asked him like 4 times what was involved in the inspection and he kept telling me only the OBD, no visual, no tailpipe, no safty. And if thats true, then I could be running a turbo with no cats as long as my tune deactivated my o2s or i just brought my excall and de-coded it in the parking lot [:D] good news for me!

696 Posts
Yeah, but if its loud as hell they might be inclinded to look, though that might be left to mr officer.


22 Posts
This may be useful:

YellaPZEV said:
*UPDATED* OBD-II / emissions / duratec scantool issues info

ok...I'm going to add to this as i come around but I notice a lot of threads involving slightly off information about OBD-II and emissions/noise testing/etc. so i figured i'd write this up here.

For some background about myself...I've been a California enhanced emissions tech for a few months now. I've been working with the state referee for the past 6 months so i can give an insight into that a little as well. while much of my info will come only about california as far as smog details go, the mechanics of failures, etc. are the same everywhere and fit for everyone. Also, the explanations of every system ever built would take forever so I'm only going to explain the newer systems on the focus.

oh and any requests to smog an illegal car will be denied...unless you want to give me the cash for the $25,000 fine up front.

duratec not communicating with scanner issues
Ok. i state this later but here it is again...the duratec uses CAN bus technology and it will be the base of OBD-III. the old scan tools do not communicate on this bus except for SPX and snap-on. you have to have a dealership or a shop with an updated scantool by one of the manufacturers above check the code. many budget code pullers will just say no codes, not no communication. but NOBODY but the above manufacturers and the dealerships will have a CAN compatible scantool.</font>

Explanation of emissions equipment
*I will list the abbreviation you usually find on an emissions label in "()" but OBD-I cars had different standards even within the same company so they won't always be this

Thermostatic Air Cleaner (TAC or ACL)
this uses a flapper valve to direct air from around the exhaust manifold where it is warm to lower cold-start emissions. it's the long tube looking thing that comes off carbureted air cleaners and TBI setups. the tube that hangs down draws the air up from around the exhaust manifold.

the flapper is usually controlled by a bimetal assembly in the flapper that slowly opens it as it heats up or a thermostatic vacuum switch that changes the amount of vacuum to the switch based on engine that opens it once the engine heats up.

PCV system
in the old days, there was no ventilation of crankcase vapors in cars. this extremely cut engine life. early systems involved a downdraft tube that simply worked by the air passing under the car creating a vacuum to pull these vapors out of the engine and it more than doubled engine life.

the system developed in the middle of the 20th century began was positive crankcase ventilation (or PCV). the system basically uses manifold vacuum instead of the blowby vacuum to draw air into the crankcase and pull the vapors out and then uses a PCV valve to regulate the flow. the early systems just vented to the atmosphere but with emissions standards coming into play, the system was later routed into the air intake.

the valve itself has a pintle and a spring that normally closes the valve to keep the vapors in the crankcase while the car is not running. the airflow lifts the pintle and allows air into the system.

EGR system (EGR sometimes with '-BP' or '-E' added to indicate backpressure or electronic)
the EGR or exhaust gas recirculation system ingects a predetermined amount of inert exhaust gas into the combustion chamber. this lowers the temperature of the combustion chamber and reduces NOx production. the different types are either activated electronically (like on a duratec) or by vacuum and a solenoid. many also depend on RPM and backpressure to operate.

on the vacuum operated system, the EGR solenoid receives a signal from the PCM at a given RPM and load setting (generally anywhere off idle and just before WOT) that opens the vacuum connection to the EGR valve from the manifold. as vacuum drops (going under load) the valve opens and allows exhaust gas to enter the intake stream.

the electronic system essentially works the same way except the valve is a stepper motor (moves a pintle in and out of a hole like an IAC) that is controlled by the PCM.

EVAP systems
the evaporative emissions system captures gasoline vapors that occur from the tank heating up and store them to be burned later so no excess hydrocarbons enter the atmosphere.

the system allows for the evaporated gas vapors to travel through a tube into a charcoal canister where they are stored. when the vehicle enters a certain set of parameters, the PCM commands the purge solenoid to activate and the engine uses manifold vacuum to allow a set amount of vapors into the intake stream and it will compensate the air/fuel mixture to match correctly.

spark control (SPK)
this is basically just all the systems that set correct ignition timing such as the crank position sensor, the PCM, the knock sensor, etc. the purpose is to set the best timing advance to maximize performance wothout raising emissions.

catalytic converters (TWC/OC) and air injection (AP for pump and PAIR for pulse system)
i put these two together because the air system essentially works to improve catalyst performance.

a basic three-way (two bed) catalytic converter is made up of platinum, rhodium, and palladium. the platinum and palladium are oxidizers that work to oxidize (add oxygen to) the CO and HC coming out of the engine into H2O and CO2. Rhodium is a reducing (takes oxygen away) catalyst that removes the oxygen from oxides of nitrogen and creates just plain nitrogen.

the reduction part is in the front of that catalytic converter and the oxidizing part is the rear. the reason is that for NOx to be reduced, there has to be very little oxygen in the stream and the O2 given off after the reduction process gets to react in the oxidizing part when gets there.

remember how i said air injection systems work to improve performance of the catalytic converter? that is why air injection tubes enter the middle of the cat. it bypasses the reduction part to keep as little oxygen as possible away from the reduction catalyst while still adding all the oxygen the oxidizing part will ever need.

the tube that attaches right out side the exhaust manifold runners is for helping the car heat up. by giving oxygen (highly combustable) to a very hot hydrocarbon mixture, you get a slight burning of the mixture in the manifold that helps heat up the catalytic converter and the oxygen sensors.

also, for a catalytic converter to work properly, the fuel mixture must vary slightly lean to rich. the reduction part requires a rich mixture (lower oxygen content) and the oxidizing part requires a leaner mixture with a higher oxygen content. so to keep both happy, the PCM switches back and forth instead of just aiming for 14.7 all the time.

Fill Pipe Restrictor (FR)
this was basically designed to make sure people didn't add leaded fuel into their unleaded car once catalytic converters came into use. the leaded pump is slightly larger and won't fit and even if it did, a tank of leaded fuel would destroy your catalyst

Definition of PZEV
PZEV means our cars emit zero evaporative emissions. This is accomplished through hydrocarbon filters in the intake, a stainless steel fuel system, and a stainless steel exhaust with two super-efficient catalysts. It also includes a 15 year / 150,000 mile emissions equipment warranty.

Our cars also fall under the SULEV or super low emissions vehicle standard of being in the top 10% of all vehicles sold in a given model year.

Removal of PZEV Equipment
In California, it is illegal to remove any piece of an emission control device...this means from your catalyst to that little filter in the intake tube that some have removed for a couple (though unverified) hp qualify as an emission control device. In the other 49 states, I believe this is the standard as well.

Interpretation of readings
Basically on a car you have 5 major gasses tested in CA (all but NOx I believe in others and the basic/new-owner areas of CA). the cutoffs listed are for newer vehicles in CA...older vehicles and other states will be different.

HC (Hydrocarbons): this is unburned fuel in the exhaust system. This is caused by nearly all non-ideal running conditions but is most drastic under misfires with readings of about 1000+ and running rich. The general rule is under 100ppm on newer cars at idle.
CO (Carbon Monoxide): this is caused mostly by a rich running condition caused by misfires. cutoff is under 1.0%.
O2 (Oxygen): this is the leftover oxygen after combustion. normal is about 1-3% (with air-injection disconnected if so equipped). Less than that indicates a rich running condition. Above means you're going lean.
CO2 (Carbon Dioxide): this is a general reading of engine efficiency. Normal is anywhere from 13.8-15% but my focus had readings above 23%. If you're lower 13%, you've got a problem.
NOx (Oxides of Nitrogen): these show up when your car is operating at over 2500* in the combustion chamber. This condition is caused by running lean, advanced timing, a bad cooling system, a bad EGR system or carbon buildup. This is a primary cause of photochemical smog so it was added to CA's dyno test in enhanced areas.

General Indicators
High CO generally indicates an ignition problem.
High HC generally indicates a fuel problem.
If high HC is paired with high CO it possibly means an ignition and a fuel problem but fix the ignition first because it could possibly be a misfire causing the high HC as well.

Aftermarket Equipment
Almost any accessory that has to do with performance short of an underdrive pulley effects emissions (even that will if there's a belt-driven smog pump). In California, any part without a CARB (California Air Resources Board) E.O. (Executive Order) number on it will fail a car under the 'other emissions equipment' section of the visual.

Granted many will pass over an aftermarket exhaust, mild cam, or porting that leaves a generally stock idle but intakes and headers are dead giveaways. You also still have to pass the sniffer test and I will tell you first hand multiple parts will fail your car even if all have CARB EO numbers. I pre-smogged a 1992 mustang 5.0 with AFR heads, BBK shortys, a ford racing cam, a bbk intake, a bbk throttle body, flowmaster full catback with high-flow cats, and a holley intake manifold. The car bombed the test under gross polluter status.

Attempting to Hide Aftermarket Equipment
Techs will be in a hurry to finish your inspection because they get paid the same amount regardless if it takes an hour or 15 minutes. That doesn't mean they're stupid.

You may be able to hide that header or missing cat with a heat shield or something to a cop but I wouldn't reccommend doing it to a smog tech. Odds are they've been working on a car long enough to know what a cat-less exhaust sounds like or a long-tube header...especially when they're at the 2500RPM (for non dyno tests) or 15mph (for the dyno).

"Knowing Someone"
Often, people will have friends pass their car by passing the visual or even smogging their vin under another car. This is incredibly illegal and results in a $25,000 fine to the tech and a 15 day suspension of the license and a probation for 3 years.

California's Bureau of Automotive Repairs (BAR) runs undercover runs to check on techs constantly... 4 of 5 shops hit up here in the desert passed a car with the EGR obviously disconnected.

Another trick is to sit in the parking lot or across the street from the station. A representative from BAR can come at any time with no warning and check invoices, the readings on the analyzer's hard drive, or even pull a just-smogged car into the shop again and repeat the test to see if similar results come up. If you're having a friend do your smog and a rep sees you've got a long-tube header, you're in for a world of hurt as well.

Fix-it Tickets
If you get pulled over for a modified exhaust, intake, or whatever and cannot provide CARB EO papers for the equipment to the officer, you will get a fix-it ticket and be required to take the car to a referee station to get it checked out. Most people just swap back the stock stuff and go back.

Only one problem with this...a guy in my driveability class had a Honda with a JDM B18C (non-us market motors are NEVER legal in CA) he swapped in one day. He got pulled over 2 weeks later and was given a ticket so he swapped his stock D16 in and had the referee sign it off and back in went the B18.

Last week the officer pulled him over again and again he had the modified engine. Problem being, the officer remembered him and looked up the vin for other tickets and his other one from a few months ago showed. The car was impounded and he was taken into custody as modifying any emissions component is a federal offense. The charges were dropped but he was told he cannot have the car back. It works just like street racing.

OBD-I was the original On-Board Diagnostics system integrated into autos. The biggest issue was it was not standard and had limited power. This lack of standardization (even in a single company) made it difficult for techs to use. My Snap-On scanner has over a dozen adapters alone for Jeep, Chrysler,Ford, and GM.

OBD-II came around in roughly 1996...there were a few select in 1995 but the majority were OBD-I systems with the standard OBD-II port. OBD-II allowed a tech to interface with the car much better allowing them to do everything from shut down individual cylinders for diagnostics to starting a car from the port.

The major difference in the smog world was how they behaved on a test. OBD-I codes could be reset by disconnecting the power and as long as they didn't pop up before the CEL check, you're fine on the visual. OBD-II on the other hand, checks the "keep-alive" RAM that holds modified fuel/timing maps to respond to a learned driving style or to bolt ons.

In a check, there is no OBD-I lead. I suspect it's because of the non-standardized systems. On the newer machines however, there is an OBD-II lead that checks the system's connections to sensors and that the "keep-alive" RAM has been set over a given number of run cycles and/or miles. a flag is set in the PCM if you haven't traveled the correct distance or mun through enough cycle and the machine sees that and fails the functional.

OBD-II monitors and trips
OBD-II monitors are just checks the PCM does on the various emissions related systems to verify they are working ok. a monitor is run under a certain set of parameters preset at the factory and if anything fails, the check engine light comes on. each monitor has it's own parameters and requirements to check and often some vehicles have trouble setting the monitors.

the required monitors (provided the vehicle has the system) are: catalytic converter, O2 sensor and heater, EGR system, EVAP system, Fuel delivery, Misfires, AIR system, and Comprehensive Component (the misc category).

Drive/Warm-Up Cycles
an official warm-up cycle to OBD-II is...
1. starting the engine with the coolant temp below 160*
2. engine running until it reaches at least 160 degrees and/or rises in temp 40*

an official drive cycle is any drive that starts with a warm-up cycle and allows all the monitors to run.

OBD-II DTC Listing
in OBD-II, there is a standardized listing of generic DTCs. the first leter tells you what system has failed (P is the most common meaning powertrain). the first digit determines if it's generic (0) or if it's manufacturer-specific (1). the second tells you what sub-system is at fault:

100 Air metering
200 fuel system (injectors only)
300 ignition system or misfire
400 emissions control system
500 idle speed control or vehicle speed fault
600 computer output device fault
700 trans fault
800 trans fault

the last two digits give the specific fault.
i.e. P0301 means powertrain fault, generic code, ignition fault, and 01 means cylinder #1 miss.

Getting around emissions by out-of-state registration
It is against the law for anyone who primarily uses the car in California to have a vehicle registered in another state persuant to Division 3, sections 4000.4 and 6700 that state that any vehicle primarily used in CA will be registered in CA and any owner who accepts employment or establishes residency must register their car in CA, respectively.

Duratec flasher (i.e. SCT)
From what I understand, the flashing from a company such as SCT cannot be detected by any means in a smog check. It's not completely confirmed but it's from a source that's been in the smog business since it's inception (literally) that I would trust on anything smog/emissions related. The only issues you run into is if it turns off any sensors that are required by the ecu to operate, if the tuning bumps your emissions too high, or your temp too high and increasing NOx.

ECU Flashing/Chipping
If you use a plug-in chip like those from SCT or reflash with the new SCT flasher being released, I strongly reccommend you reflash or detach it a week before your test and then detach the battery cable overnight. That will clear the "keep-alive" RAM and put you back to a stock program. Then drive it a few times during the week and complete the required cycles/mileage and take it in.

On a side note...I believe the duratec flasher from SCT may not fail the functional. My understanding is that if it just reprograms the timing/fuel maps in the PROM without messing with any sensors, the machine will just think that's how it came and you won't fail provided the other sensors work correctly and the remap doesn't put you too far out of range that you get a biased O2 sensor code or something (i.e. removing fuel at idle a little on a bigger cam and advancing timing to use 91 fuel may still pass). don't quote me on this and i'd love to see if it would be true.
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