on my 95 firebird with the stock 3.4l what would cause split blms? as in left bank 128 right bank 105 in cell 16(idle).two brand new 02 sensors ,new plugs and wires, no error codes (i am using tunerpro rt). injectors not leaking. what should i be looking at to fix this? cant pass emissions nox over double the standard in az.

Could be a blown diaphragm on the fuel pressure regulator causing raw fuel to be sucked into the intake through the vacuum line.

the problem is on one side and the fuel pressure regulator would effect both sides i believe. i could be wrong on that. fuel pressure at the fuel rail was good. is there a way to test the fuel regulator?

also when i pulled the vacuum line there was no gas present.

After some interwebbing, I found this info, which gives me a bit of an idea:

Causes go on to include running lean, egr issues, carbon buildup, and overheating.

You have indicated the computer is accounting for something, pulling more fuel to one side. That may be the indication you are looking for. Sometimes if injectors aren't flowing right, clogged, etc, it can cause this issue. It also indicates carbon buildup as well could cause this. If an injector is clogged, you will have one lean cylinder, and 2 rich cylinders, which will wreak havoc on emissions.

When was the last time you were on carbon patrol? I am thinking a good engine/fuel system cleaner (seafoam or techron) is in order, along with some spirited driving. If the issue persists, I would swap injectors from one side to another to see if the problem moves. Also look for vacuum leaks as well. Dryrotted vacuum lines are a possibility too.

I have tried swapping injectors and no change, as for carbon and such i completed a valve job not to long ago and its clean inside. i think i found a spark plug that looked odd and will be trying out new ones today. ill let you know if that was the problem. if the plug wasn't firing then that would explain all the extra fuel going thru the cat. i think anyways.