A tale of two O2 Sensors
Thread Starter
Launching!
Joined: Feb 2018
Posts: 224
Likes: 31
From: Bismarck, ND
A tale of two O2 Sensors So, I finally install the new and improved ported #862 heads on my truck. After priming the oil, I put in the sparks plugs and the engine fires right up. Sounds good so I have the wife jump in to go do some shopping.
We drive for a few miles and then the engine idles rough, smells gassy, runs bad so we limp on home. I set the parameters on the Edge gauge to read the O2s, long- and short-term fuel trims. When cold in Open loop it is OK. The first 5 minutes or so in closed Loop it is OK. Then Bank 2 O2 reads only up to .200 volts and short-term trim goes to +54.
The O2 have worked OK for 80,000 miles, right? I must have an intake leak. So, I remove the intake and find maybe a leaking area on the bottom of #8 intake. Check the intake and it is warped a good .020”. So, I file and sand it flat, take off about .040” of the stand offs to make sure the gaskets are compressed, put the intake on and it is the same thing.
Then I switch the O2s from side to side and the over rich goes from bank 2 to bank1. Order a pair of new ACDelco O2s and installed them and problems fixed. Funny thing is that I did not receive a check engine light even though I ran it a couple times. Only thing I can figure is that I removed them to paint my mid-length headers and that made one them MAD.
We drive for a few miles and then the engine idles rough, smells gassy, runs bad so we limp on home. I set the parameters on the Edge gauge to read the O2s, long- and short-term fuel trims. When cold in Open loop it is OK. The first 5 minutes or so in closed Loop it is OK. Then Bank 2 O2 reads only up to .200 volts and short-term trim goes to +54.
The O2 have worked OK for 80,000 miles, right? I must have an intake leak. So, I remove the intake and find maybe a leaking area on the bottom of #8 intake. Check the intake and it is warped a good .020”. So, I file and sand it flat, take off about .040” of the stand offs to make sure the gaskets are compressed, put the intake on and it is the same thing.
Then I switch the O2s from side to side and the over rich goes from bank 2 to bank1. Order a pair of new ACDelco O2s and installed them and problems fixed. Funny thing is that I did not receive a check engine light even though I ran it a couple times. Only thing I can figure is that I removed them to paint my mid-length headers and that made one them MAD.
