Hey all, its been awhile, ive been working, but i do enjoy reading the posts. Anyways, my problem is this. Every morning when i start my car, and i press the accelerator, the car hicups BAD. As in, i go for half throttle and the engine studders and the car bairly accelerates. This problem goes away in about 1 minute and never returns till the car has sat for a long time (like over night). Just had some work done, like a tune up, valve job, and oil change (including changing to synthetic oil). Could this be the problem, or maybe o2 sensor (hasnt been replaced in awhile). The car is a 90 525i.

Thanks,
Jason