I noticed today that if i am just cruising and i stump it to the floor my car seems to backfire threw the intake into the airbox, at least it sounds that way. Now i have heard of this before being a loose timing chain, however, i did take the dist cap off and see if the rotor turned it, moved a little but nothing big. I also heard this problem when my TPS went bad. (I orginally had a problem with hesitation, but it turne dout to be bad plug wires, so it fixed it, but i did replace the tps, then that new one went bad and but back the orginal one. I'm wondering if that could do it?) The other thing i heard was valves could be loose? Whats the most common fix to this, or should i not worry about it for now? Thanks