Whenever i cold start, i hear these pops as i let off the throttle. I think it started after i filled my tank with Amoco 93? Am i running rich or is this crapola gas?

 

Are you sure its not just backfiring?! Thats usually a common thing. If I remember right BP owns amoco and I've never heard anything bad about their gas.

-Alex

 

You may just be backfiring.

Jeremy

 

mine pops at idle all the time but i dont have any cats or exhaust or a perfectly tuned ecu. i vote your fine

 

Mine normally makes random puuuuupapuuuuuuuupupuuu kinda sounds. I think it stops once the engine is fully warm.

 

is backfiring bad for your car??? or is this totally fine~~~ backfiring doesn't hurt anything???

 

mine too, its normal

 

It's just a partial ignition of unburned gas in your tailpipe as it exits and is heated by the hot metals of the muffler(s). Rotaries are particularly prone to backfiring because of the way they operate. Only severe backfiring will damge anything, and even then it's only going to cause serious damage to a cheap muffler. Otherwise it's not really an issue.

 

It never hurt anything on my car

 

remind me never to buy that BP crap again.

 

What about popping/backfiring under boost?

 

My car does it too . . . .

 

It shouldn't be backfiring under boost. It is normal to backfire when you let off the throttle after boost though.