My car is still backfiring under heavy acceleration. I changed the plugs and tightened up all of the exhaust. It still boggs down a little under quick acceleration. I think the fuel filter might be cloggged but can that cause backfire? When i step on the gas, my air/fuel gauge says it gets really lean but when I let off it gets really rich and then goes back to normal. All i really wana know is can a clogged fuel filter cause backfiring?

 

Sounds like to me you may have a timing,ignition problem. The fuel filter if clogged will make it run very bad maybe even to the point of backfiring or not running at all. Change the filter then check that timing..Bottom line thou keep it simple..I thought I had a major problem myself turned out the wires, plugs, cap and rotor were shot. start with the obvious then go from there..

 

I would say: Yes, a clogged fuel filter could cause backfiring from the lean condition. I'm not saying that's the problem though!