Pls help, can anyone tell me what causes backfiring on my car?

 

unburned fuel.

 

It's not a bad thing ... most of the time. It's just unburned fuel exploding in the exhaust.

 

that's the little 'fart' sound right?

 

That's good to hear. So is there any way I can burn all the fuel so there is no backfiring? Why arent all the fuel burn?

The backfiring on my car is mainly when I drive slowly.

 

yeah, i usually only hear that sound driving slow or at idle...

 

Put the pre-cat back on. That will get rid of the backfiring. Just do like everyone else, live with it...

Also, use the search. This topic has been beat to death..

 

Ok thank you Mahjik, so it means i have to live with it if i had removed my pre-cat.

 

There's extra fuel to burn largely because the stock ECU runs the car a little rich to be on the safe side, and also because for some reason Mazda put a MAP sensor on a turbo car instead of a MAF sensor. I wouldn't really worry about it unless you have heavy carbon buildup around the end of your pipe, then you're running way too rich. If you think it's a big problem, you can run a different ECU or stand-alone and have the maps corrected ... but the first thing I'd do is make sure my ignition system was healthy if you think it's a serious problem. It can happen when you drive slowly, and it also has a tendency to happen when you suddenly pull off strong throttle due to a sudden drop in fuel consumption.

JimmyJimboJet, depending largely upon the exhaust setup (and furthermore to actual fuel maps and porting setups), it can range from a little fart sound to a deep "thwonk" sound.

 

Really?? Shows how much I actually pay attention. Just every once in a while I come around to help a few people ... and keep the rice in check.

 

Sure, just use that handy search function:

https://www.rx7club.com/forum/search...der=descending

 

thanks guys

 

The RX-8 has some modification to the intake and exaust ports that will burn more fuel. that'll probably get rid of backfiring for the most part in them.. I'd like to see someone do an RX-8 porting job on a 13B.

 

hmmm, In my opinion that is one of the cooler things about the rx7, I dont know why you would want to get rid of it..... I mean shooting flames out the back of your car, I dream about that kinda stuff.... and its nothing to really worry about so why not?