Car stored for 6 years. Ran great before. Changed oil, plugs and wires, air, fuel, and oil filters. Computer passes, no codes. Checked all vacuums. Still misses.
Car miss. Computer pass, no code. Changed plugs, wires, fuel filter. High idle. on 2000 Pontiac Grand Prix
I would start by checking the coils for spark ...just pull the plug wires off one at a time to find out which cyl is missing...what kind of scanner did you use to check for codes if it is just a code reader that wont help much ...you need to use an OBDII scanner so you can get a data stream !
poss bad fuel?