I get this popping noise when i let off the throttle when the car is in gear (clutch still engaged) the haynes manual says its afterburn and then lists a bunch of probable causes. Anyway, i dont really feel like fixing something like this if it isnt hurting anything. thats the deal though, is it hurting anything?

mine does the same thing i didnt worry about it though https://www.nopistons.com/forums/pub...>/rolleyes.gif

Don't worry about it if the car is running well.

why does this happen anyways? I had something similar in my gxl for a period of time, I think it was my TPS being out of adjustment, cuz there seemed to be fuel getting injected on deceleration which was being combusted in my exhaust, i had one instance where it afturburned so much after a long 130mph blast into downtown chicago, going through a tunnel right before the downtown area it illuminated the entire tunnel and made a couple jump to the ground who were getting things out of the trunk of a car on the side of the road, like a gunshot. Was mildly amusing but probably scares the **** out of people behind me. At least you're not likely to get rear ended when your car reeks of 2 stroke (no cats and premix) and shoots flames on deceleration. Actually, this didnt happen during deceleration, it happened when i got back on the gas in 3rd at like 6k rpm after downshifting from 4th to decelerate. At that moment it seemed like there was a buildup of unburnt fuel in the exhaust that got ignited when i got back on it. Anyone have a more technical explanation?

do u still have your air control and check valve? It helps elimate that.

No ACV (or check valve), that went when I installed the RB header. What exactly is the afterburn caused by? I thought the ECU causes fuel cut on deceleration, where is the fuel coming from that is causing the popping? I always assumed it was my worn+misadjusted TPS and old (100k+ mile) injectors leaking, I've been presuming that it will go away after my rebuild with the RCE injectors and new TPS.

I'd agree with them my subie did that...sometimes on decell others when I hit 3rd real hard..made a nice flame..scared the **** out of some guy in a honda trying to play around...if the car is running good don't worry too much...It does get annoying tho