When my car is idling, the exhaust sounds like it is going *rmmmmmmpop pop rmmmmmmmmm pop pop rmmmmmmmm*. They aren't loud pops, but clearly interruptions in the exhaust's tone. I think that my cats are collapsed or clogged. Can anyone shed some light on this for me?

 

mmmmmm pop, pop pop mmmmm pop....
isnt that a Hansen song? hehe

What mods do you have? My FD pops regularly like that at idle, it is a pretty normal thing.

 

I asked about this before and the general concensus is that it is the exhaust piping expanding and contracting due to the heat that causes the metal popping sound.

 

could be backfiring. Is it running rich?

 

This is when it is running, I have no mods, and at idle speed. I don't know if I am running rich or not.

If rotaries just do it, then OK, but if they aren't supposed to, then I would like to know!

 

My car does that sometimes. I think it occurs mostly on cold start-ups. It sounds like little mini-backfires. I've assumed that my timing may be slightly off b/c of the mods. I haven't had mine for long, and the last owner put on the intake and exhaust mentioned in my sig. Should I get it tuned?