Bit of a problem here.
My CA is misfiring at idle, a lot.
When I start the car the AFR starts at 12, goes up to 18+, then back down to 14.6-15.
After that AFR is all good, almost doesn't move but I still hear and feel misfires.
When cruising at vacuum AFR shots up to 18+, can't accelerate unless I go deep throttle. Once I reach around 2.5 PSI of boost, car runs perfectly all the way to 14 PSI. Better than ever since I just changed the plugs and packs.
It's pretty much only misfiring under vacuum. Since full boost is fine, it can't be fuel or ignition or compression.
I'm at a loss as to what can the problem be. Any ideas?
I'm running a stage1 chip (already tried stock ECU, no change).