hey
Whenever I decelerate my car sometimes makes 1 or 2 popping noises from the exhaust. It might my my wastegate opening but why would it open at 1,000-2,000 rpm? It might also be my engine backfiring which i'm guessing would be bad but i think an engine backfiring is 100 time louder then the sound i'm hearing. any one ever heard of this happening to a turbo car?????

 

It's normal. Prolly unburnt fuel hitting the cat. My Subaru does it all the time.

 

Does it seem like you're loosing pressure (boost)? The only two remedies to your problem I can think of is you might have exhaust leaks, or you're running too rich. Check exhaust pressure, then check fuel with regulator. Good investment for your car is to purchase a fuel pressure regulator, or at least a gauge.

 

i have just a intake and exaust, and i get it too, its only noticablewhen decelarating and when im listening to the exaust.

Link

 

When a engine backfires, it is loud. I know from exp. I was taking my friend to the beverage center, he went in and i just had the car idling, the throttle cable was sticking so it was idling at about 3,000 rpm's. I wasn't thinking anything of and i turned it off because he was taking a while and i wanted to save gas in the beast. This old lady was walking in front of my car going into the store. When i turned the ignition off, the car started to chug and i heard a VERY loud boom (the rear of the car lit up)! The lady looked like she was shot, kinda froze in place and then kneeled down. I got out to make sure she was ok, didn't want to give her a heart attack or anything. I apoligized for scaring her, trying to be nice and all and she just scolded me and went back to her car and left. Pretty funny just thinking about now anyway.

 

For just NA cars (I have the same problem), I've heard two possibilities...

1) It takes about a year for a new exhaust to truly break in (that seems long to me, but, I've heard anywhere between 500mi to a year, so, it's just a matter of who you talk to).

2) I've heard that on some new cars, it takes a while for the ECU to "relearn" the engine's characteristics, and therefore runs the engine a bit rich, and has a tendancy to dirty up the spark plugs. I've heard this from a few different sources, one of which saying that it's pretty much Mitsu and Nissan that has this problem more than others, so much that they say that it may be necessary to replace the spark plugs.

Now, before I get flames, let me say that I know none of this for a fact, just passing along info that I have gotten. Really, I'd like to know how to solve it myself. I'm kind of sick of the "bb gun" shots I'm getting after declerrating and sometimes during shifted. Thanks.

 

mine does it also, but only in 1st gear and when I full throttle and let off. it only started once i got my new exhaust, but it doesnt bother me

 

Probably running too rich and excess fuel not being burn't and burning up in the exhaust.

Did this start after fitting the larger injectors (Which were a lot bigger than standard) then this is definitly the cause.

My drag car is really bad for this N/A but is consistent with running rich in low rpm levels.

David Thomas
www.rpw.com.au

 

the injectors are definatly the cause. I'm getting my car dyno tuned today to fix this problem.