This 1987 ford mustang lx 2.3l auto a/c car with the EGR delete/open header is giving me some problems. When I start my car it runs good. If I start it warm it only takes 30 secs for it to start this stumble. If it’s cold it has to get fully heated up before it gives me any trouble. The stumble only last for 20 secs and if you try to give it any throttle it only stumbles until you give it full throttle. But if you wait it will clear up.

If you drive it hard on a hot day it will try to...

1987 ford mustang temporary stumble