Studder at constant speed only

[clarkie6]

Hey all, I just found this site, so far it's been very interesting and I hope some of you galant fans can help me out. When driving at a constant speed, and only at a constant speed, the car will sporadicly studder for about 3 seconds and then be completely fine for a while. I've had a bunch of problems recently and have just put in a new battery and alternator. I also used some intake cleaner to clean the throttle body, I think I used too much and had some rough idling for a bit, and then low idling, I moved the screw in the tb to get the idle up a bit and it's running great now. Also, I have code P0505 that just popped up with the check engine light. Any advice is much appreciated.

[Brian03Galant]

I have the studder prob as well. happened after I changed the timing belt and balance shaft belt. Kinda aggravating really. I watched the rpm gauge when it starts to studder but no drop. I am curious on a fix as well