ok i had my tour worked on today got the timing belt and drive belt changed it had problems with idle before i got the belt changed then whne i got teh belt changed it got worst but its only at idle and when putting it in drive other than that it runs fine the machnic did advance the intake cam to give me more hp do you think that could be my problem or could it be some thing else its a 97 tour gl sport have changed the plugs and airfilter put and muffler on it the car has 91000 miles on it do you think i should change the plugs and pvc and egr vaulves
