My 99 Contour w/2.0 DOHC and AT, has started intermittently stalling when I am braking hard, especially if I am turning at the same time. It seems to stall once I slow below 10 mph. The CEL comes on intermittently with the only code being P1131. When I say it is stalling intermittently I mean it has happened maybe 4 times in 3 weeks. After the engine cools the problem seems to go away for awhile. Gas mileage is right where it has been. There is no shudder or anything when it stalls, it just seems to shut off. I took it to one shop and they wanted $250 to diagnose. And their guys were looking under the hood for the scanner connection instead of under the dash so I pulled it out of there. I was just hoping that maybe someone else had experienced something similar and might point me in a direction. I have 103,000 miles on the car. The timimg belt was replaced at 80k. The only thing I have done to it lately is to replace the rear brakes. One suspicion I have is the PVC valve but I am reading that it is an all day job to replace a $2 part (ridiculous engineering!). The local Goodyear shop didn't want to even do it! The fuel filter was replaced 4 months ago as well.
-
Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.
You can register to join the community.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
CEL P1131 Stalls when stopping
- Thread starter notbob
- Start date
[FONT=arial,verdana,helvetica,sans-serif]P1131[/FONT][FONT=arial,verdana,helvetica,sans-serif]Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1. [/FONT]
you should change the O2 sensor, but that should cause stalling.
I suggest checking the IAC
you should change the O2 sensor, but that should cause stalling.
I suggest checking the IAC
yes it will be the sensor before the cat, or the one between the engine and the cat
the down stream sensor is after the cat
the down stream sensor is after the cat
The reply about the brake booster is really interesting really interesting. 2 1/2 years ago I had the starter repaced and the shop accidently broke the the vacuum tube coming out of the booster. They replaced it for free, but you post made me curious so I did a quick look over it and when I pulled on the end by the intake manifold it came right out. I pushed it back in but it did not feel like it was in very tight and I thought there was a collar you pulled to lock this on. I cannot get to it to see what is going on until I tear the air intake hose and resonator, and probably a lot more, off. I talked to friend who used to be a Mazda master tech and as soon as I told him what it was doing and the code that was set he said I had a vacuum leak somewhere. Maybe I'll get lucky and snap that hose securely to the intake manifold and cure the problem.
This problem has become more complicated. The problem seems to be intermittent but is worsening. It started occasionally idling really rough and when it di it would buck at highway speeds. It was drastically overcompensating for a lean condition because, I could smell the unburnt fuel. I found a vacuum leak on the brake booster hose going into the intake manifold and corrected this. I also replaced spark plugs wires (they were original anyway, it was time), cleaned the MAF and reset the computer. It drove fine for 4 days and then it started acting up the same way today. I was waiting to get on the freeway and it started to idle really rough. I got on the freeway and it accellerated fine but as soon as I readhed speed and backed off it started bucking. It did this for about 2 minutes then the CEL (P1131 again) came on and then it started running fine. Right now I am looking at the MAF, the PCV and the brake booster system. I think at this point I have screwed the O2 sensor and that is aggravating other things but I don't want to replace it until I figure out the real problem for fear of frying a new sensor. Too much for me to figure out. I am taking it to a local garage known for its diagnostic work and see what they come up with.
I took the car to the garage (Petty's Automotive for anyone in central Ohio) and they found that my pcm was programmed wrong. I guess there are 2 fuel trim settings and both were set to -16, they should both be 0. They reset it to factory settings and replaced the upstream O2 sensor and it runs much better. The idle is still a little rough at times but I think that may be an IAC starting to go south.
projectSHO89
Hard-core CEG'er
There was nothing wrong with your PCM's programming. It has been trying to compensate for a vacuum leak (most likely, perhaps the O2 sensor) and the fuel trims will revert back to the previous readings in due course if the original problem remains.
Steve
Steve
I took the car to the garage (Petty's Automotive for anyone in central Ohio) and they found that my pcm was programmed wrong. I guess there are 2 fuel trim settings and both were set to -16, they should both be 0. They reset it to factory settings and replaced the upstream O2 sensor and it runs much better. The idle is still a little rough at times but I think that may be an IAC starting to go south.
from what I have seen from datalogging the fuel trims are dynamic. I suppose ideally they should be zero meaning the exact amount of fuel is being used. But they are suppose to move to adjust fuel flow for the current conditions.
So I agree that nothing is wrong with the pcm and that it is just trying to correct for the problem and is at its limit hence the problem.