I own a 01 jetta with 160k and the other morning when I started it it had a rough idle, it was vibrating to car. I know its a deisel but it was like I had a plug that was not firing. I decided to move it to take my truck and in like 10 feet the roughness stopped and has not been back. Could an injector cause this? Is there a cleaner that is safe for them? Is that something they do with 100k mainatance?Or do I tell the wife it's fixed? Thanks