Code PO131

After installation of Head Gaskets & LIM Gasket, on 1998 century 3.1, no leaks, starts ok, runs at highway speed fine. After about 20 minutes of driving, engine stalled at lights, developed a reving up and down of idle speed, then stalls. Will not idle in park, revs up and down, about 30 seconds then stalls. Done idle relaearn, but did not help. Code scanner says PO131, sensor 1, bank 1. Low voltage. i think it fouled out from all that carbon i loosened up whil;e in there? would applying dielectric grease to the 0-2 harness termianals effect voltage, and shouild i remove it? Or you think o2 sensor is shot? Thanks guys.

I would replace the sensor. Generally if you had water in the combustion chamber and it went through the exhaust system it will damage the O2 sensor. The dielectric grease on the terminals isn't a bad idea but I suspect the sensor is shot.

GTP Dad, I will get a new o2 sensor today. it will be a bear to remove, i am not looking forward to it. Mine is welded in there pretty good. i will report back on results, to help others, as i have always been helped. Thanks to everyone who has helped me in the past. i appreciate, and enjoy this site.

GTP Dad, Replaced the 02 sensor as suggested. Problem solved. It did not look good, all gunked up.The head gasket, and lim gaket replacement went well. I used your write up to do it, great piece! Thanks again to all.