fast50hz

iTrader: (1)

Car starts up fine and idles normal when cold, but when its warm and it is restarted it acts like its missing and running on less than 8 cylinders. It takes about 30 seconds until this stops and then it returns to a normal idle. It smells like its running rich, i havent pulled the plugs yet. It sometimes sputters and loads up. Car seems like it would be faster accelerating if it was running leaner. Could it be bad o2 sensors ? Where should i start?

Thanks for any help guys

MODS: 2000 z28 with m6 TSP 5.3 stage 2.5 heads, torquer v3 cam ,ported TB, full bolt ons, ls6 intake, custom true duals, centerforce clutch, aluminum flywheel , dyno tuned on mustang dyno 418 rwhp and 438 rwtq .

bad_408_vert

iTrader: (6)

Put a scanner on it and see what you get back.

If your car was stock, I'd say maybe the 02s because I 've seen the same thing.

Also, who tuned the car / how long ago was it tuned and when did this issue occur?

*Edit* If, when tuned. Did you keep the MAF? Could be just a dirty MAF sensor.

zracer323

iTrader: (12)

Check all spark plugs and wires. If the o2 sensors are going bad then it should throw a code.

fast50hz

iTrader: (1)

Ok guess i have some places to start looking to narrow this problem down. I did just check the mass air sensor and the 3 bars were dirty, so im gonna get some maf sensor cleaner tomorrow and see if that helps. Car was tuned a few years ago by EPP i believe, but i bought the car from my brother after all this was done.

NC98Z

iTrader: (1)

Definately clean the MAF. Use a can of CRC MAF cleaner and not some kind of electrical cleaner.