2000 DTS 194,000 miles, 2000 DHS 203,000 miles
So I just bought our service writers 2000 DHS for my wife for 1500 bucks. I fixed the head gaskets with studs last year for him. Every since it's had a rough idle. I have a plethora of injectors, coil cassettes, Plugs, coil boots. Swapped them all out with known good parts. Cleaned the throttle body, idle air control valve. No codes but the idle is rough 90% of the time. Just giving it a little gas smooths it right out. Been thinking I could try a new IAC valve but sure wish it'd at least throw me some kind of code. I really just dunno what else it could be that I'm overlooking.