Hi,

I have noticed, while in the garage, I have the car running at idle. I will rev the engine to about 4,000 RPM's and notice sometimes I will get one "backfire" or "pop" when coming back down to idle. Just curious if this is normal.

1995 993 with 50K miles.

Thanks in advance.
-chris

 

My 95 does exactly the same! Love the burbling of the engine!

 

I installed de-cat kit to my car. Now this "afterburning" is very frequent, almost every time when brakeing with engine. Very nice sound, especially in the tunnels.

 

Hi Chris,

The "pop" sound is normal. The fuel shut-down
is abrupt with these cars, due to the sudden
lean mixture when backing off the throttle.
This results in lower emissions, and adds dimension to the already cool engine sound.
The abrupt lean mixture also causes the "lunging"
during light throttle use in 1st/2nd gear.

All the best,

 

my supercup exhaust(or lack of exhaust) has the same effect! (huh, I can't hear you)

 

I've noticed that my '95 993 has been doing the same thing lately, though it does it when the engine is cold, and when I press the gas pedal. It sometimes hesitates then pops before the engine revs. I need to replace the plugs and clean the ISV, and if that didn't fix it, I was going to post.