Contour Enthusiasts Group Archives Forums General Troubleshooting Check Engine Light

My car is running fine and then the check engine goes on. I turn the car off and then back on and the check engine comes back on and the car is still running fine. I take the car to Autozone and they tell me the code for the check engine light is P1131. The only problem is Autozone does not know what P1131 means. What does P1131 mean?

When my car was under warrantee I had a similar problem and Ford fixed the problem by replacing the DPFE sensor. Could the DPFE sensor be the problem? What is the DPFE sensor?

Thanks for any help!

check codes here:
http://www.contour.org/FAQ/FAQ.php?s=probs&display=checkengine

Thanks

P1131 Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1.

How do you fix this????

If you run a search on the code, you will find quite a few posts, including:

http://www.contour.org/ubbthreads/showflat.php?Cat=&Board=trouble&Number=20355&Forum=trouble&Words=1131&Match=Entire%20Phrase&Searchpage=0&Limit=25&Old=allposts&Main=20355&Search=true#Post20355

Well today I took the car to the Ford dealer. One of the rear oxygen sensors is bad plus the mass air flow sensor. Total work $505.00, needless to say I paid my $55.00 diagnostic fee and took my car home. The dealer told me that one of the rear oxygen sensors went bad and that sensor was very hard to get at. Which rear oxygen sensor is he referring to? How hard would it be to replace this oxygen sensor? The Ford dealer almost wanted $300.00 to fix it.

The dealer also told me that the mass air flow sensor was reading 149 and in Houston it should be reading 155 (see level). A reading of 149 is what the mass flow air sensor should be reading in an altitude of 2500 ft. Does any of this make sense?

Any help would be greatly appreciated.

Thanks

2000 SVT

The MAF is probably fine.

You need to replace the rear bank O2 sensor -- it's under the coil pack area. Kind of hard to get to, but not impossible.

-Lance

thanks Lance! I will try to fix it myself.

Originally posted by lkinley:

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The MAF is probably fine.

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I second that. In my experience, an O2 sensor is far more likely to fail. Plus, a failed MAF sensor would impact both cylinder banks, not just Bank 1 (I forgot to check if you have a V6).

I remedied P1131 purely by replacing the Bank 1 upstream sensor. It's somewhat of a pain to get to on the Duratec, but more than one CEG'er has done it successfully.

Good Luck!

The dealer probably was referring to the MAP (Manifold Absolute Pressure) sensor, not the MAF (Mass Airflow Sensor).

BTW, I replaced that rear, upstream O2 sensor this summer on the wife's 98 'tour. Took less than an hour and the sensor cost was about 70 bucks from AutoZone (Bosch sensor). Removal of the coil pack was definitely needed.

Steve

The oxygen sensor you guys are talking about is in front of the firewall. If it is, it will be one hell of job!