I have noticed since I bought my Z that when I start it up with the engine cold (especially now that it is getting colder), when I left off the gas for my first shift, the engine backfires a lot. Now it is starting to back fire for the first few shifts. Is this a problem or should I not worry about it? I'm straightpiping it past the cats by the way.

 

It's perfectly normal. My WS6 wakes the neighbors when the weather is cold and I have the cutout open. Actually, even with the cutout closed the exhaust pops a little until my 2nd or 3rd shift.

The car runs rich at startup, so there is unburnt fuel, which is what pops. <--- that's how it was explained to me.

 

The same thing happens to me and i have a stock system when car is cold and i nail it and back off it backfires a little then it's fine when it warms up.

 

my 2002 does it too....pretty cool IMO

 

after i got my LT headers and got rid of the AIR system it quit doing it and i miss it!!!!