I've been chasing a problem with my 97 LT1 for a year and a half. Starting to get pretty pissed.

I get a persistent SES. Codes translate to Multiple Cylinder Random Misfire and Bank too Lean (both banks and the lean codes always come simultaneously). Lean codes are more common than the misfire codes.

Things replaced include:
MAF (GM)
All 4 O2 sensors (Bosch)
New Plugs (NGK Iridium)
New Plug wires (Magnecore)
New Optispark (GM)

In addition, multiple concentrated efforts to find a vaccuum leak have turned up nothing. This has not been cheap nor has it involved 5 minutes of effort. I am getting tired of this.

For the most part, the car pulls as hard as a stock LT1 should but these codes are driving me nuts. This morning, I ordered a new AC Delco coil. I suppose after that, I will order a new Ignition Control Module and the harness that runs between the coil and the ICM.

What am I missing?

 

Have you checked the fuel pressure?

 

No. I suppose I should. Thanks.

 

My GM vehicles will not run with Bosch O2's. Highly suggest you stop throwing parts at the problem. After checking fuel pressure, it's time to start doing things that cost little or nothing to do. Can help when you get to that point.