Contour Enthusiasts Group Archives Forums General Troubleshooting code P1131

cel light keeps coming on, shows code P1131- h02511, i know it's the o2 sensor but which one, front or back and any ideal how expensive they are.

That one is the rear (next to the firewall) upper sensor (before the precat). It's also the hardest to replace. I was able to do mine a few years back fairly easily by renting a free O2 sensor replacement tool from AutoZone. The kit included an offset 3/8 drive socket that you just put a few ratchet extensions on, lay on your back and twist the sensor right off.

Before you do this you might do a search for "1131" and read about some of the other people here who have had the same code. Not all have been a defective O2 sensor.

i was told by ford it was the front, good thing i checked before i bought it, also they say it's $164.66 for 1 sensor.

That's quite expensive. AutoZone also sells the sensors. I don't remember exactly what I paid a year or two ago but it's not anywhere close to $164. If you don't need it by tomorrow you can get a huge CEG discount through Bill Jenkins at Signature Lincoln Mercury in Las Vegas. Contact info is at the bottom of this link: CEG Parts Sources

Remember, do a forum search first before you replace the sensor. People have reported things like bad wiring, corroded plugs and manifold vacuum leaks causing this code to appear.

Sensor is about $65 at AutoZone for a unit from Bosch. Excellent quality part.

Replacement is a bit of a PITA, but what isn't?

Steve