Finally Resolved Stumbly Idle Problem

[Thieu]

The culprit was.......... drumroll........









The EGR valve. I tried lots of stuff before realizing that the EGR was clogged up and remaining open at idle, therefore resulting in a stumbly idle. I didn't bother replacing it, I just removed it. I cut up a piece of sheet metal and screwed it on the intake manifold hole. As for the exhaust manifold, I stuck a nickel in the hole and used the screw thing that was on the EGR tube. Worked like a charm. The car isn't 100% smooth at idle, but I'd say the shaking is 95% gone and the car isn't missing/backfiring at idle anymore.