Originally Posted by lt1silverhawk
What should happen to a Chevy 350 TBI engine if the Idle Air Control Valve is disconnected? Engine is running, warmed up, and the vehicle is parked.
Read through this the first place I would go is the EGR they wear from the exhaust gasses and get leaky at idle where they a normally not functional. This will upset the idle while not throwing a code as the code only comes on if the EGR fails off when it should be on. The other potential failures are not monitored. This will cause an unstable idle but not always all the time.