ok, so ive been working on the damn thing for over two years - i dont have a house, so car's at the college shop and i usually dont get to work on it more than 9 hours a week which sucks but thats beside the point.

i have a 2004 GTO LS1 all wired up and running, everything nice and smooth but it failed smog in December. HC is high and NOx is sky high((

since originally i was running 02 computer that is programmed to work with AIR, i switched the computer to GTO one, no AIR.im assuming that should help

but now i have opened can of worms - i have codes for
all O2 heaters - since O2 were supplied by the shop that did the harness, im changing O2 to stock (gonna finish today - and scan it, hope it'll help)
EOP - engine oil pressure, i took out sender to hook up my gauge
A/C request bla-bla-bla smth - i dont even run an a/c
Engine speed - my tach stopped working
it is missfiring (that was before O2 swap and regulator)
and my alternator is not working with new computer - new alternator is on the way

i also had a suspesion that fuel pump i got did not have a regulator, so I put in a Corvette filter with one built-in

i need some ideas, what else might be wrong?my MAF is from the same shop as harnessa nd O2 - can it also cause me problems and i should hunt down stock one?i mean readings on scantool does not look a way of...
what about a/c code? can be since O2 heaters use the same circuit as a/c solenoid for supply voltage (i got the supply side, and the return one, which would be a/c request is setting the code)?what if i take the wire out and just run ignition voltage to the bulk of wires?

what about O2?i doubted that all 4 wires are open within the harness and i checked all my grounds from the harness to the chassis - they all fine
what about tach?i had to switch it to 4 cyl signal to run with Camaro computer, but what about GTO?is it 8 cyl signal? i got Autometer tach

does anyone know thread on the ls1 EOP sensor? i was thinking of putting a 90 degree elbow to run both from the top

also does anyone know when exactly computer grounds stuff - like heaters for example? when key on, engine off, or when engines running???my computer from a running GTO, so I doubt it had a problem with heaters, although there is no way to check now(

PLease, I need some help and ideas of what else to check!!!!
Thanks

 

ok, turned out that a/c, EOP and tach crap wouldnt turn MIL on or cause drivability issues, so on to the 02s...
does anyone has any ideas what can cause 1 bank to run rich and another to run close to bias voltage?

 

You have already tunned all unwanted stuff out of the PCM ?

I have just seen this with an LT1 motor....what he found out was a leaking ground in the 02 sensor harness.

What I would suggest is go back to basics and test for leaking ground with a multimeter.

I am no expert and I am sure others will chime in.

 

It sounds to me as though there are at least a couple of things going on, probably the best 'first step' that I could suggest would be to take a little bit of time under the hood & look for loose or open grounds, broken/frayed wires, etc. I had a boss one time who was really good with electronics, & he told me that "A lot of the time, the best troubleshooting tools you have are right here!" (pointing to his eyes). I've found that to be helpful on more than a couple of occasions.

Also - I seem to recall an old thread where someone was having oddball rich/lean issues like what you're describing, it turned out that he'd accidentally switched the O2 harness connections from one side to the other - so that when the ECM saw bank 1 going lean, it was actually bank 2, & the ECM was maxing out the correction trying to bring things back in line, & just making it worse. (It almost doesn't sound quite like what you're seeing, but it's worth checking out.)

Also, you shouldn't need a 90* fitting if you don't want to use that, you could get a T-fitting & run both, OR just tap the gauge into the little cover/fitting that's just above where the oil filter threads on - as shown in this post.

Good luck with it.

 

Thanks guys, Ill go through O2s again tonight..if anything ill just switch them and see what happenes