97 bonneville stall,irrattic idle

I have a 97 Bonneville this is the problem,when car is stopped in drive it idles down low and acts like it is going to stall,also when it is coasting into a drive it will either stall or act like it is going to,if it dose not stall it will pick up real quick in its own,then after it is in park it will idle up acouple of times and then even out.new fuel filter,plugs,checked idle control,throttle control,cleaned throttle body,replaced vaccume lines,pvc valve,when I didn't put the o ring on the pvc valve it runs great,put it on and I have the same problem. Any help out there? Thanks

change the spark plug wires? any check engine codes?

I have replaced the wires also. There is no engine codes. This is making me nuts! any other suggestions?

HI everyone!!!!! I found out what the problem was! I encourage anyone having similar problems to save themselves alot of $$$$$ by having the vaccume power booster checked to make sure it is not faulty.This is a common problem, cost of booster $140.00 and I also learned there is updates that the computer on these car need!!!!!! $65.00 I really hope my problem will help others have this checked before spending big $$$$ on sensors that are good.

Where's the Vacum Power Booster located & what does it do for the engine? Or is this part of the power brakes?

The power booster is located on the drivers side firewall,it is part of the braking system but it draws vacume from the engine,if it is bad it creates a bad vacume leak.