I have a 2007 Chevy equinox AWD. The issue started as a P0420 check engine code. Car seems to run normally other than when the code is popped the car shifts somewhat sluggishly.
Things I have replaced so far:
Both 02 sensors(the downstream was pretty clogged with carbon so worth the new part)
Catalytic converter(since returned because I’m sure it wasn’t the problem)
Spark plugs and cables
2 separate Engine coolant temp sensors(this is my main issue)
From my understanding, if the computer is getting innacurate readings of the engine’s temperature it could cause the engine to run rich. That could cause the P0420 code, right?
The reason I thought this could be the problem is on a long drive I noticed that my temp gauge was pegged and pulled over immediately. I opened the hood and everything seemed to be the normal operating temperature. So I figured it was the engine coolant temp sensor. I replaced the part twice and after resetting the code the gauge pegs and I get a message that says engine hot ac off.
The weird part of this is that as soon as the check engine code pops the temperate gauge functions properly and the car no longer gives the message engine hot ac off. I have reset the code three times and the same issue occurs.
I’ve check the wiring harness to the sensor to the best of my ability. I’m not sure what else to do. Any advice from some more qualified folks would be greatly appreciated.