im pulling a code 5 from my CEL and im assuming the wiring going to the o2 is faulty and im pretty sure i know where. Cause i just replaced the sensor itself about 30 miles ago. but from other posts ive read in a search someone mentioned just unplugging it and it would run a stock fuel mixture. That true? but if its not getting a good connection now wouldnt it just do that anyway? i cant fix it till this weekend cause i dont have my soldering kit. err. could explain why my truck is running pig rich.

 

1. You can check the O2 sensor directly with a voltmeter between OX1 and ground on the diagnostic connector. It will swing from 1v to about 5v 7-10 times in 10 seconds. If you don't get that, something is wrong in the O2 sensor circuit.

2. Pig rich? The O2 sensor is designed to make fairly subtle adjustments; the computer can make a pretty good guess at mixture just from air flow and temperature. (Which is why you can start the truck when the o2 sensor is cold and not reading.) If you're running pig rich you probably have some other problem, which you ought to find before you whip out that soldering iron.

 

thanks. i know running rich is most likely due to the TPS or the water temp sensor, but im sure the bad o2 connection doesnt help. just havent had the time to work on everything.