Hello,

This is a completely stock 1992 Corvette LT1 engine. The issue I am having is that my left side (bank2??? scanner wtf?) is running extremely lean and my right side extremely rich. When it gets into closed loop it will run the BLMs 108/160.

Well... Sensors where shot, but the problem still persists. As you might have guessed, car runs like CRAP.

I am trying to get this issue resolved. With the sensors unplugged I will read consistently 448mv on the right side but WILL VARY on the left side!

Now I have tried to search for the wiring issue on the left side and the only other possibility I find is to redo the wiring for the left side and see how it goes.

Any ideas? Bad ECU? That is what I am inclining myself that could be the culprit.

Thanks

Chris

 

When the O2 sensor is unplugged, a scan will return the reference voltage....~0.5V and it shouldn't vary at all. While a bad ECU is almost never the issue, it seems like it might actually be the case here. I doubt the wiring would be the cause as you're reading an open circuit. Any chance you can swap in a known good one and check it out?

 

You can go to autozone and buy one put it on and if it does not fix the problem their kinda like wallmart just take it back in the package and tell them it didnt work. Should get your money back. sometimes the sensors get so dirty also they get wrong readings you might have to clean them or replace them usually about every fifty thousand miles which will improve your gas mileage anyway.

 

Bank 1 = driver's side = Cyls #1/3/5/7.

Bank 2 = passenger side - Cyls #2/4/6/8

 

I know.. but the scanner is putting it backwards... at least it has correctly labeled left and right side...

Anyways... What i did was switched the sensors connectors and .... honestly... the readings didn't change in banking.. so.. either i have a real issue with the ground for the sensors or the PCM is faulty.

 

Still not sure what you mean by " but the scanner is putting it backwards"... I've never seen a scanner that shows codes as "left" and "right".... it usually "bank 1" and "bank 2".

Is it possible you have a plug wire running parallel to the O2 sensor wire for the one that "WILL VARY" (whichever side that one is)? That could induce a cyclic voltage in the sensor harness wire.

 

I see my name in the title, but I have nothing to add to what others have said (they are doing a good job). If you want something from me personally, email me.

 

Ive never heard of a scanner doing that either but true the pcm could be bad usually there good for the life of the car but ive heard of some going bad in other forums. You should check your grounds and the wires like the other guy is saying that should always be the first thing.

 

Thanks for pointing that out Rob... we really do discourage naming ("paging") individuals in the forums.... sort of disrespectful to the other people who can also offer valid advice.