i have a 99 z, car has a lid fast toys ram air and exhuast.
the car is throwing a bank 2 sensor 1 lean.
car surges like it has a vacc leak......which is what i will be testing first.
but what else could cause a lean code?
the only things i can come up with is iac, egr, or an inj. but the iac and egr would affect both banks, and the inj would not cause the car to die when idling....any other thoughts?

 

Bad O2 sensor will do it. I had a broken wire on one, and it was reading lean, but the plugs showed rich. Replaced the sensor, problem solved.

 

thats what ive been told last night.....thats weird, never heard of an 02 causing the car to stall, and usually gm cars run rich with any problem.....
but thanks! gonna fix it today

 

ok well that wasnt it. replaced 02 still has a miss, still running like ****, and still throwing a lean code, which is not constant...i really need this fixed, its my dd. car is costing me a fortune to drive right now.
what could cause just one bank to run lean? and what could be so hard on it that it would die, but not throw a miss fire code?

 

Mine was doing the same thing but it was for bank 1. I did what NVR SPDS said to do and replaced the 02 sensors, it did nothing. Then I cracked open the valve covers and saw I had a floating Valve Stem Seal replaced it and bam, fixed the problem. I don't know if this has really anything to do with that code but it worked for me and it is just a idea.

 

I have the same problem with bank 1 my car does not die and it is random. I swapped the left and right 02s and the problem whent away for 300 miles or so and now is back.. I can not find any vacume leaks and have not taken off the valve covers to look at the valve terrain.. The car runs good.

 

well i figured the problem out... it showed its true colors yesterday...finall bank one and two lean, and the iac was maxed.....i had a bad pvc valve which caused the the hose to suck shut, and caused a vacc leak....so multi problems.lol
so im super happy now...thanks guys for the help.