A few months ago I gutted the cats on my 06 gto ( thought I might of had a partially clogged cat turned out I didn't) anyways this was early spring so the weather was fairly cool and I only had some backfiring when downshifting. NOw that the hot summer weather is here the car is backfiring when accelerating during shifts and backfiring a lot more when downshifting. I havn't had the car tuned yet because I am going to be doing some mods first. Is it Just because the car is running to rich without the cats? Would a tune help or are there other things I should check?