backfire?/ running rich?

neon angel · Post by **neon angel** » Sat Jan 06, 2007 3:24 pm

ok when im accelerating hard i tend to backfire. then when i brake hard from draging it tends to doit again when shiftinf into 1st. what i have is an 05 sxt ATX with ngk iridium plugs. this girl who races cars who works at advance auto parts said it sounds like im running a little rich ? so how would i go about leaning it out? she told me to buy a k&n so i did?

OB · Post by OB » Sat Jan 06, 2007 10:06 pm

most cars run rich from the factory, its safer than tuning them lean, which can cause much bigger probs and reliability issues than rich does in the longrun. However, many cars are also programmed to lean out during cruise to save fuel and lessen emissions. Neons are no different; thats why they run so clean and get fairly good mileage. However, when operating at WOT, i wouldnt doubt seeing rhe AFR diving far below stoich as a precation to avoid detonation (which is due to excess heat).

anyways, to make a long story short, i doubt it's a backfire that youre hearing; its more likely afterburn, which is completely normal for any car, but neons tend to be noisy about it. its simply the fuel burning up in the cat/exhuast. If its happening while youre on the throttle, then that a different story. afterburn usually occurs when letting off the throttle, and when downshifting. I assume you have an exhaust/aftermarket muffler? if not then its highly unusual for u to hear any sound from the car, except for the standard engine whine. hope that helps.

Post by **Canada** » Sat Jan 06, 2007 10:51 pm

orangeblastsxt wrote:most cars run rich from the factory, its safer than tuning them lean, which can cause much bigger probs and reliability issues than rich does in the longrun. However, many cars are also programmed to lean out during cruise to save fuel and lessen emissions. Neons are no different; thats why they run so clean and get fairly good mileage. However, when operating at WOT, i wouldnt doubt seeing rhe AFR diving far below stoich as a precation to avoid detonation (which is due to excess heat).

anyways, to make a long story short, i doubt it's a backfire that youre hearing; its more likely afterburn, which is completely normal for any car, but neons tend to be noisy about it. its simply the fuel burning up in the cat/exhuast. If its happening while youre on the throttle, then that a different story. afterburn usually occurs when letting off the throttle, and when downshifting. I assume you have an exhaust/aftermarket muffler? if not then its highly unusual for u to hear any sound from the car, except for the standard engine whine. hope that helps.

Quoted cause this guy is pretty much dead on. Good call D

neon angel · Post by **neon angel** » Sun Jan 07, 2007 1:42 am

thanks for that i decided to get the k&n and i bought a set of magstar 8.5 race wires (they were the optinal/performance wires that were pulled up for an 03 since performance parts for an 05 is still kinda ne according to advance.)

Dutch_Neon · Post by **Dutch_Neon** » Tue Jan 09, 2007 2:12 pm

I have the same problem but mine does it in all gears and when accelerating. It runs very rich, almost flooding the engine till there is hardly any performance. Lot of knocking coming from the engine and transmission. It basically runs awfull and uses fuell like a *(&^%$#
Techie here said it might be the lambda sensor...

00element10 · Post by **00element10** » Tue Jan 09, 2007 2:52 pm

my car used to backfire out the intake, and it was always fouled sparkplugs.

tooslow · Post by **tooslow** » Wed Jan 10, 2007 4:19 pm

yeah try too some champion spark plugs see if that works
and if that does not work

also is iat senser plugged in your cold air intake it could make you run rich if it is not in the intake

if all those don't work I would look into a o/2 senser