my car is backfiring through the throttle body....

ok, here is the story... I just changed the oil, and It was a little behind so the oil was dirty and kinda think, so we changed it and put a new filter on. anyway when I crank it it runs great, everything is fine... so the next day I ride the car to school and i notice that it is smoking quite a bit when i pull out. so from there it got worse... so after that day i parked it and didn't ride it anymore.... well about a week or two later I had to ride it to go pick up my g/f and on the way there it started messing up really bad, when you get down on it a little (example: passing another car) it stutters and starts missing, almost cuts out completely and backfires through the throttle body.... now mind you it is still smoking quite a bit... it isn't shooting a flame out of the throttle body that i can see it is just puffing air, and puffing doesn't really descride it... it is really popping bad, sounds like it will blow the breather lid off or something

does anyone have any idea what could be causing this???

thanks for any input

What else did you do when you did your oil change? did you mess with the ignition wires or Cap/rotor? A backfire through the intake is either timing related or firing order related.

I'd look into your cat or exhaust system. Sounds like there might be a lot of backpressure in your exhaust somewhere.

"A backfire through the intake is either timing related or firing order related." Absolutely not true. Sure those can cause that, but they are not the only causes. If you are running real lean, that will cause the backfire also. The data you gave is rather limited, and anyone here is really just shooting in the dark trying to guess what is wrong. That being said, you mention the car smoking, and I assume from the way you said it, that is something new. If you somehow contaminated the O2 sensor, that could cause a problem with mixture, which could cause your problem.
I have no idea what the "smoke" is, perhaps it is not smoke, but steam, from a blown head gasket, or a cracked head. Try pulling the codes on your car and see what that tells you. At least then you have a starting point.
Tom

my car does this simlar thing at night but it cuts out and usally blows a big flame out the exhaust and picks back up sometime but it gets worse when i give it gas