I have an 03 ram 1500 with about 86000 miles i have had a engine code that p0131 that says low voltage 02 sensor bank 1 sensor 1. I recently changed the upstream sensor. As soon as i change the sensor It threw code p0132 which is now high voltage in sensor 1 bank 1. Not only that on a cold start the idle wants to fall on its face, since i changed the sensor. At first I thought it was just because the computer was reprogramming but im thinking its a bad aftermarket sensor. Any input would be great I dont know if i should of went with a mopar o2 sensor. thanks

 

You may find you need to put the Mopar one in, but if you have not already, try re-setting the PCM and see what that does for you...

 

DTC's can be kinda tricky and don't always point to the exact problem. Take a o2 code for example...the prob could be the sensor, the wiring harness, could be running rich/lean on a bank caused by a problem elsewhere. Duringcold starts/open loopthe o2's are bypassed and the truck runs off of pre-mapped fuel/spark tables. When you say the idle "wants to fall on its face"....does that mean it's stumbling or is it more of a erratic/searching idle?

 

falling on its face i mean erratic searching idle
Ive rest the code and instead of my original code it now a high voltage instead of a low voltage .
The idle was never like this with the old sensor in.
thanks for your help