why is my car back firing..

[Kid Racer]

Hey guys i fixed my y pipe that connects too my manafolds i got it all tightened up.....but at the end of my pip be for it goes into my muffler it has a hole there and its still back firing and whne it does it shoots flames out of it...my cat. is gutted...does any one now anything taht i can do too solve this problem...

[NJSPEEDER]

the only way it would shoot flames out the exhaust is if the engine is running very rich. is your O2 sensor hooked up and working properly? if the O2 goes bad or gets misreads the computer goes into a safe mode that dumps a bunch of extra fuel in.

[Kid Racer]

how do i check this out..too see if its bad or what not i can i hook up a fuel gage presure and see if its getting too much fuel...

[johnjzjz]

Originally Posted by Kid Racer

how do i check this out..too see if its bad or what not i can i hook up a fuel gage presure and see if its getting too much fuel...

i dont want to know how you know its shooting flames out of a hole on the muffler, and how is it you are under the car looking but -- and who might be reving the engine while you look --- have one of the guys that has a clue look at it -- dont get hurt -- jz

[Kid Racer]

johnjzjz.....nah i had my brother rving it up a litl under the hood and the whole isnt in the muffler its on the bend of my pip that leads into my muffler but i was be side the car looking at it....

[johnjzjz]

Originally Posted by Kid Racer

johnjzjz.....nah i had my brother rving it up a litl under the hood and the whole isnt in the muffler its on the bend of my pip that leads into my muffler but i was be side the car looking at it....

an exhaust leak can sound like a snaping sound and almost sound like a lifter ( flywheel crack if thats what you might think ) i have been fooled and doing this almost 40 years -- jz

[Kid Racer]

but it sounds like it is comeing right from the fly wheel i mean sound is right there ...

[johnjzjz]

Originally Posted by Kid Racer

but it sounds like it is coming right from the fly wheel i mean sound is right there ...

Than the bolts that hold the converter to the flex plate are loose ( remove inspection cover and check the 3 bolts buy tightening ) -- or worse the flex plate to engine crankshaft have come loose ( trans out to fix ) -- jz

[Kid Racer]

see i tightened the ones that hold it too the t.c. and tryed to move the center of the flex plate with my flat head but i couldnt i dont know ima juss get my dad and we r going to put it up and jacks and stands and see if we cant locate the ploblem....

how do i check this out..too see if its bad or what not i can i hook up a fuel gage presure and see if its getting too much fuel...

[Batman]

If the O2 is bad it will throw a check engine light. You probably won't see it in the fuel pressure.

[johnjzjz]

i would start with the plugs and wires -- as you did not say the check engine light is on -- maybe a crack in the dist cap - look in the cap too see if it has signs or ( tracking ) it looks like a black carbon shaky line from any of posts inside cap to one another -- but i am not sure if you even have a cap on that car --- jz

[Kid Racer]

well my car does have a check engine light on but it has always been on cause of my egr valve system..so maybe its now the fuel thing too

[NJSPEEDER]

one way to prevent the check engine light from the EGR is to take the check valve that is on the charcoal canister, should be behind the driver side head light, and plug it into the vacumm line that goes to the egr from the egr controller. just plug the extra vacuum ports on teh check valve. it will be enough to make the computer think it is operating the egr.

[NJSPEEDER]

the easiest way to make sure the O2 sensor is working is prolly jsut to get a new one. they are only about $20 and a fresh one will work better anyway.