Bank1 and Bank2 way off on fueling...

I have up to a 12% swing from the left to the right with STFT, the O2's are all out of sync and the wide band O2 is also all over the place.

I have spent several hours looking over the headers for leaks and there just are no signs of leaking at all period. I'm confident there's no exhaust leak so lets take that out of the equation.

I then took my infra read heat gun and measured the headers about 2" from the flange. All the tubes on Bank2 are far hotter, in fact several hundred degrees hotter then Bank1. This now backs up the O2 readings that Bank2 is lean.

The car runs good, has a lot of power but it has a shake at idle and just off idle plus it sounds like the cam is far larger then whats in there and I'm wondering if the huge imbalance between banks would account for this? Plus I would like it to be correct and as even as possible

What would make an entire Bank lean?

Lee

BTW, this is my firebird with a vortec 454 and 0411 with custom OS

Hi Lee,

Check for intake manifold leaks.
Check for O2 sensor not working correctly (swap OS2 across banks).
Check for injectors not flowing correctly (swap injectors across banks).

Are you getting any misfires (check compression/leakdown)...?
Are you getting any internal coolant leaks (causes misfires)(pressure check cooling system, block test kit)...?

This did the same thing when I had a holley intake on and now it's an edelbrock. The gaskets looked great when I took them off so I didnt see any signs of leakage.

With 2 wide band O2's plus the original O2's in at the same time to me rules out an O2 problem plus the temp difference supports the O2 readings.

I ruled out injectors because each cylinder was within 50 degrees of each other, so if it was a bad injector it would show up with the temp gun.

No misfires. I did a compression test and leakdown test last year and it was near perfect. I've only put on under 100 miles since then.

No loss of coolant, oil is clean.

The car runs good, it just has a huge swing in readings. I was going to drive it tonight without STFT on and see how it feels....

Could a ground issue on one side cause this? If so, then why does it run so strong?

I've had this same problem with 97/98 pcm's and have never got it figured out. I just ended up shutting off stft at lower rpm levels. I wish I had a better answer for you.

As for a ground issue I never found one either but had that thought on the last one I tuned. I even went tried tuning it with hptuners without any difference.
And ya I have ls1edit too lmao