created the thread Could my intermittent bank one oxgen sensor problems be caused by a tuning issue?
" I have been getting a persistent 2c3d code (PreCat 02 sensor lines/wires, Bank 1) on my 335i running a custom Wedge tune. Now I am getting a 2c77 intermittently as well (AfterCat 02 sensor signal, Bank 1)
I have replaced BOTH of these sensors in the last six months- it made no difference.
I cannot for the life of me figure out what it could be other than (1) something in the tune my car disagrees with or (2) the actual engine wiring harness.
Is theory # 1 even plausible? I did notice when I went back to the original map for about a week the code didn't generate. But, to be fair I have gotten similar "false reassurances that all is well" while tuned since then as well. Critically the code seems to generate more frequently while engine braking.
If if it could be a wiring issue, are there any diagrams on what wires to look at? Replacing the whole harness is at least 1k, and simply do not have it right now. "
Today, 06:31 PM