I have noticed a strange idle loop while in park only. The instrument needle does not jump up and down, I can only here it. It has been doing this for the past few days. I ran codes and nothing came up. The idle is perfectly fine in reverse or drive. Any ides what that could be? I tried doing a search but came up with nothing. My car is an auto with 92,000. I have recently done a tune-up including plugs, wires, cap & rotor, I also have a new TPS, cleaned and checked the MAF and IAC, new dizzy, new ignition coil, and new ICM. I am not sure what else it could be? Thanks for any help.