Once in a while not very often 2-3 times a year in hot/warm weather only I will go to heavily accelerate from a stop I will get a backfire, its hard to tell if it is comming from the intake or the exhaust. It happend yesterday right infront of the local parts store so I pulled in and hooked up their code reader......nothing.
My timming chain was just done in the last 3k miles it does need a tune up but then again it did this when all the plugs and wires were new too.
Any ideas?

 

Try doing the seafoam thing. Usually a backfire is a lean/rich condition. Or injector timing issue. Given how rarely it does it, don't expect it to be easy to find.

 

I am a huge fan of sea foam and use it once every other month.........its time again so its on the order for todayd fill up.
Thanks.