Backfiring

RiceBox said:

My car backfires when decelerating. What are the possible causes and ways to fix it. BTW I've been getting pretty crappy gas milage too, so I'm thinking it might either be dirty injector or time for new electronic bits (wires, cap, rotor)

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*****That's a tough one, Ricebox. If it had the GA16i engine, it would have an AB [anti-backfire] valve on it. But I just checked, and the E16i [at least the US version], does not have the AB valve, which would allow extra air into the intake manifold, to lean the mixture and prevent a backfire. Frankly, I have never seen an E16i backfire on decell. The only thing I can think of, that might cause a backfire on decell, is an exhaust leak forward of the cat converter. If you had a rich mixture [and it sounds like you might, due to your bad fuel mileage complaint], and an exhaust leak, it would backfire on decell.

The exhaust makes a popping sound when decellarating. When I slow down for the corner on my street all I hear is *pop pop pop * The exhaust system is pretty new so I doubt there is a leak. This weekend I'm going to change the wires, cap, and rotor (the plugs are new and properly gapped). Those parts are atleast 2 years old so they need to be changed anyways. I really think it is a ignition problem because I have a mis-fire when the engine is cold. Then again it could also be part of the emission control system. GRRR So many things to check!!! If it continues I'm going to check the sonsors with the multi-meter I got for my b-day Oh yeah I just added some STP fuel injector cleaner to see if that clears anything up.

i dont know if this is a common problem or not, but my car eats caps and rotors, i can notice the difference by changing it every 3 months!
just a thought

I changed the cap and rotor today. Made a big difference. My idle is MUCH smoother especially when the engine is cold. The contacts inside the car were HEAVILY corroded. I had one little problem, the screw that holds the rotor broke. There was a little bit of swearing but I got it out, and got a new one. Works pretty well now, there is very little backfiring and only when cold.

well, ill definetly have to invest in a cap and rotor too because im having the same problem. i was told that it was backpressure because of my new exhaust system that i added not too long ago. but this definetly something to look into. i love this forum. southern states nissan will never see my car thanks to u guys.