ok i got my car tuned over the summer and a little after that my idle started acting up. i don't know if its the tune or maybe i'm in need of some new spark plugs. i've been running the tr6 plugs for a year and have about 16-17 passes on them with a 100 shot n20 and about 5 or 6 passes with an 85 shot. the car feels like its going to stall when i pull up to a light after the car i fully warmed up. falls to about 300-400 rpms and then when shoved into nuetral it hesitates and then raises very slowly. any input on this problem would be most appreciated.

 

if it was tuned in the summer time that could be part of it if the tune was not done correctly, and the car just responded better in hotter weather. could be low voltage as well