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HOW-TO: Mechanical CEL Fix for a Header

62K views 137 replies 48 participants last post by  j_thielmann 
#1 ·
Well, there's always threads on how a newly-installed header has caused the check engine light to come on. Here's a tutorial to circumvent this problem. A tune can disable your rear o2 sensors, but in States whose smog stations plug into the OBD-II port, a disabled o2 sensor will instantly fail you for smog. This is a mechanical fix; it does not turn off or disable any of your o2 sensors.

Tools required:
Strong drill
1/2" drill bit
Vise (preferably)
Crescent wrench
Anti-seize copper sealant
Jack and jack stands


1) First off, you need to check how many o2 sensors you have.









2) If you have THREE like in the picture, you will need to buy TWO packages of these:





There should be two anti-foulers in each package. Get these exact ones. You can find them at Pep Boys, Kragen and most auto parts stores. If you only have TWO o2 sensors in your exhaust manifold, then you will only need one package.






3) Now, you'll need a 1/2" drill bit, a vise and a fairly strong drill. Make sure your drill bit is sharp. You will need to drill a 1/2" hole using the drill bit through the anti-fouler, essentially opening up the hole that already present. For people that have THREE o2 sensors on their header, you will need to drill two of these anti-foulers. YOU NEED TO DRILL ALL THE WAY THROUGH THE ANTI-FOULER, OTHERWISE THE o2 SENSOR WILL NOT SCREW ONTO IT.










4) Ok, so now you will want to disconnect and unscrew the #2 and #3 o2 sensors from the car. For those that only have two o2 sensors, you only need to disconnect the last sensor. You'll need to jack up your car to access the #3 o2 sensor, so take car doing that. Put it under a jack stand or two.



5) Take one drilled anti-fouler and screw it on top of an un-drilled anti-fouler. Use some anti-seize on the threads. Now screw the #3 o2 sensor on top of the the drilled anti-fouler. Use some anti-seize on these threads as well, but don't overdo it and slop it all over the sensor. Screw this double anti-fouler assembly into the header bung, using anti-seize on the threads again. (For those of you that just have two o2 sensors, do this step for the #2 sensor; you are done)

It should look like this:










6) Now take the other anti-fouler you drilled and install that on the #2 o2 sensor, using anti-seize. Here's how it should look:





And just for clarification, do NOT put any anti-foulers on your primary o2 sensor. That one monitors your engine and has nothing to do with emissions. LEAVE IT ALONE!!








7) Make sure everything is tightened down. Unplug the battery for 10 mins. Plug it back in, lower the car from the jacks and take it for a spin. Hopefully you have the same luck as me and your CEL should not come on again.
 
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#2 ·
this works too...ive seen it in person. sick ass set up
 
#9 ·
i ant gatta go till 2009 but its supposed to be done in 08 but than in 07 they said it would be done and its still here wat BS.. around here 7 countys make u do it the other dont so i dont see the point
 
#13 ·
nope.

from what i've read, it moves the o2 sensor out of the direct path of the exahust gas, making it read a lower level which makes your car think that the cat is still there and is cleaning the air.
 
#20 ·
do you think this method should work on a cosworth header? I can't even see the plugs for the sensors in their picture
 
#27 ·
dammit i rounded the nut on the bottom 02 sensor cant get it out ... guess im going to have to pull the fing header back out..... man this just makes my [:)][:)][:)][:)][:)][:)]g day ive never been so [:)][:)][:)][:)][:)][:)]g pissed off
 
#28 ·
dude, just leave it. It's not worth pulling the header off IMO.

you might end up damaging the sensor trying to get it out as well, costing you more time and $$$
 
#34 ·
yeah my dad said he can prolly get it off with his channlelocks or what ever he called them hes a machanic. he cant beleive i put the header on my self but cant get the o2 sensor back out lol i must have tightened it to tight and that low one is a pain while its on the car to do anything with...
 
#31 ·
^^^i agree. headerwrap is fantastic, and proven to:

1. keep underhood temps down.

2. keep the exhaust gases hotter, thus maximizing flow.

What do you think is a better way??
 
#35 ·
im not bashing. im just stating that the guy doesnt have any evidence
 
#33 ·
wait, who's bashing who? what do u mean honhon? i just agreed that header wrap is a good thing. i was gonna use it myself. im not trying to bash anyone. i agree with syz. if i bashed someone, sorry!!! [wave]
 
#38 ·
6 beers and being mad i got the sob out of there.... wow i locked some visegrips on that bad boy and yanked and yanked and it came loose.. i checked the top one and it was like easy to take out i was like damn.... so im resetting the computer now ill know in a few days if the light stays off i really hope it does.
 
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