Quote Originally Posted by wyliec View Post
I just changed out the stock exhaust and went with an aftermarket one.

When I downshift and decelerate there is no backfiring. The backfiring takes place, as an example, when I downshift from 2nd to first and as it is slowing I give it the gas. If I don't give it the gas to speed up, it doesn't backfire. I have an SM5 and it will do that no matter what gear I downshift from.

I actually believe the spyder was doing that before changing exhaust; it just wasn't as pronounced b/c the stock exhaust was quieter.

Is it time for an O2 modifier? There are no other performance mods on my 2008 spyder.
Yes, and up to you.