[twcblackhand6970]

First time posting here. My girlfriend's car, which is a '00 ZTS Focus, starting sputtering and missing a while back and we didn't know what was happening. Then it gave the engine light a few days later which was the P1131 code. I was wondering what the "usual" suspects were for this code. The problem occurred out of nowhere. The symptoms of it are a higher than normal idle rpm, lot of engine noise (ticking), sputters any time on the gas, and bogs down while accelerating softly but seems to clear up a bit while getting on the throttle. It's her daily driver so hoping I can fix it without having to drop it off at the shop for a couple of days.

 

[penguin]

Google is your friend:

http://www.google.com/search?q=dtc+...s=org.mozilla:en-US:official&client=firefox-a

"DTC P1131 indicates the system is correcting RICH for an overly LEAN condition. The Heated Oxygen Sensor (HO2S) voltage is less than 0.45 volts. This is usually due to a vacuum leak after the MAF. It can also be caused by a bad PCV valve or PCV system hose. It can also be caused by low fuel pressure or a plugged injector."

 

[focusmaniaczx3]

possibly fuel pump or filter as well i guess. if its leaning out or isnt getting enough fuel. i know that there was a fuel pump recall on the 2000 zx3 focus but im not sure about the zts. call your nearest ford dealership, ask them about the fuel pump recall, and give them the vin # off the car. they will tell you if that car is elidgable for the recall and if it is wether or not it has been done on the car yet. if the recall hasnt been done on your GF's car they will put a new fuel pump in for free. it will only take a few hours. even if that isnt what is causing the problem it would be good to get it done anyway

 

[penguin]

> a higher than normal idle rpm,

That symptom suggests a vacuum leak after the MAF. Probably wouldn't hurt to clean the MAF, but since it came on so suddenly, a vacuum leak would be the first thing I'd check.

 

[djmontara]

well, best thing to do is check your fuel trims.. That will rule out a vacuum leak.. I say, first change your fuel filter. Then check your spark plugs and your spark plug wires

 

[norcalfocus01]

if the ZTS has the SPI motor it is probalay a vac leak. that is what i had a few months back. mine was the 90 dergre hose rigth off the back/bottom of the thortle body. let me see if i can find the thread i had one it.

 

[norcalfocus01]

http://www.focusfanatics.com/forum/showthread.php?t=175021

here is my link with pics of damaged piece and oh use carb spray to find the leak it worked great for me!

 

[penguin]

> I say, first change your fuel filter.

Logically I would agree, but practically speaking, there's a couple of reasons it might be wise to check for vacuum leaks first:

(1) I don't see how a clogged filter would result in a higher than normal idle speed, which a vacuum leak would, and,

(2) It is much faster and easier to check for vacuum leaks than to replace the filter -- I generally try to eliminate the easiest possibilities first.

 

[twcblackhand6970]

Sorry it took so long for me to get back here, been busy.
Well, the plugs are good, that was the first thing I checked when it started acting up. I changed the fuel filter out next which was dirty and put fuel system cleaner (Gumont stuff). I was thinking it was a vacuum leak due to the high rpm at idle and sputtering like it was trying to die. I'll check the hose to the PCV valve hose tomorrow after work, but where exactly is it located? Also I'm going to spray the MAF sensor with some cleaner.

 

[djmontara]

on the back of the intake manifold and the 90 degree vac hose on the throttle body...

 

[twcblackhand6970]

okay, I'll check it out when my gf gets home from work. I'll get back to yall after to let you know if this solved the problem.

Just got back in and couldn't find the leak, but I can definitely hear it now. When I sprayed throttle body cleaner around the TB while it was running it seemed to clear up a little. I checked the four vacuum lines on the back of the TB and they are all good. What else could it be?