From the top; here's what happened. I have an 02 T/A with a stroked LS2, heads, cam, the works. In the beginning, I had it on a dyno and tuned. Later on this guy out in Arizona tuned it for taller tires. At the time the IAC was shot and he tuned the car to basically not stall. I think he adjusted the idle and cracker. Then I replaced the IAC a few months later. Ran it during the winter without a thermostat and notices a lot of oil consumption and performance loss. I installed a thermostat and it still burned a lot of oil and hesitated a lot at WOT, then one day it started having problems starting, like it was missing for a few seconds then would fire up. It got progressively worse and eventually started backfiring and wanting to stall and the idle would climb to 2K then drop to 500 with backfiring every few seconds. It was also throwing the insufficient switching code. I parked it for a while until a guy I met hooked his laptop to it and noticed the right bank was running way rich but the left was fine. Then we checked the plugs, they were all blackened. I did swap the plugs with NGK 4177, fluids have been replaced and have MSD wires. I drove it to work this morning and at first the clutch was making so much noise, I couldn't tell anything else. The clutch calmed down and the car drove and ran smoother the longer I drove it. While in neutral it would rev up to around 2K then slowly fall back down to around 900 rpm; then a few backfires. Just a few minutes ago I fired it up and it never idled above 1K and ran very rough; like it's missing but I changed the plugs yesterday. It really sounds like half the engine is working. As it warmed up the idle started to slowly get steady, then backfire and the idle drops and stumbles for about 10-15 sec, then the cycle starts over again.
It was recommended to do a compression check and also get the PCM tuned again. I plan on doing both as soon as I can find a tuner close to Abilene. Mission impossible…
Looking for as many ideas and opinions as I can.