Okay, I searched but didn't find anything that was what I was looking for so I'm just going to ask. Didn't know what thread to put it under as so posting here.

Alright, cold morning today and I warmed my car up all the way before leaving for work, on the drive to work, I downshifted to second gear and as soon as I rev matched I heard a "pop" sound from my intake. When I think about it, this has happened once or twice on cold days before and I'm just curious on why it did that.

I have a 2003 350Z 6speed and I'm running the JWT pop charger on it.

 

Well..."pop charger"

 

Lmao, should haven seen that one coming :P

 

You ran rich, hydrocarbons in the exhaust = POP. If it keeps happening, do a scan on your short term fuel trim and timing angle. Could be a normal result of an aftermarket part without a corresponding tune as well (?)

 

Only happened a couple of times on cold mornings, could be that I'll look into it! I have test pipes and had my catback on before too, friends said they have seen me shooting some flames, so I am probably running a bit rich with the mods. Thanks for your input!

 

Used to happen to me in my Civic after I installed my CAI. It would usually happen in cold weather and I would upshift and get back on the gas fairly hard. It sounded like an intake backfire.

Zakmartin, IIRC an intake backfire is caused by a lean spot, basically not enough fuel for the amount of air coming in causes this. This can probably happen since the weather is cold and just the right factors can create this, like air density.

I wouldnt worry about it unless it starts doing it all the time.

Question, are you aggressive on your downshift or more relaxed?

 

Intake, test pipes, and catback? You'd be running lean, not rich.

 

Yup. My civic used to do it when I had intake, header, test pipe, and exhaust and I was running slightly lean until I got tuned.

 

Gotcha, thanks for the clear information.
Umm, I downshift relaxed for the most part but the couple times that I've heard this pop is when I downshift hard into 2nd gear on cold days.

 

Sorry, you're right. Could be a dirty MAF (?)