when im cruisin on the bridge or highway at like 75-90, and let off the gas. my car backfires. i have a tuned PCM but would getting a dyno tune fix this problem or would it be someting else?

 

Do you have cats? Removal of catalytic converters cause this sometimes.

 

Any mods? Year? Etc.? More details.

 

Did you have it tuned recently? DFCO values could be skewed slightly and causing you to go in and out of DFCO causing backfires or popping.

 

MasterT- nah i have gutted cats
RamAir- 93. lt4 hotcam, gutted cats, 3" cutout, shorties,fastchip PCM tune
Lswho- just a mailorder tune.

 

Did you have it tuned recently? In other words did it start after your tune?

 

I bought the car like that...but was never really in the mood to push it. I did forget to mention that i can smell gas outside the car, standing behind my car.

 

Answer onr question for us. DO you have cats on the car?

 

The tune has to be off if it smells like gas, probably running too rich. I'd send the PCM into pcmforless or Madtuner and have them redo it.

 

Or he can have a leak and be "lean" and the PCM is flooding it trying to fix it.

 

hey just yesterday i drove my car for about 20 miles..when i got to my friends house, i turned the corner and the car started to either backfire or make a popping noise almost every 4-5 seconds as i press on the gas. (sounds like...pop.....pop....pop pop....pop) this just started yesterday night.


just went under the hood and seen this hose and took a picture...
hose looks like it next to the opti.

 

Looks like a vacuum line? Or might be the vent for the opti? Hard to tell with the pic.

Edit-Cant be opti vent can it? 93s didn't have vented optis?