My scooby seems to backfire quite a lot. Makes me grin, but is it meant to do it?

It's got a decat on it. Don't know if that makes a difference or not.

Could it be some sort of overfuelling type thing and the reason for my 18mpg?

 

decat will make it pop a little. maybe maf sensor is weak or 02 sensor. dumpvalves also casue popping and banging. i love it to be honest

 

ive got a de cat and mine pops every now and then ,did it more when first put it on,i love it to

matt

 

the faster u drive the hotter it gets the more it happens.its prob not healthy but i know the dv helps and it has a faulty 02senor.also an induction kit

 

ive just been fully de-cated and ive noticed a few pops between gear changes sometimes a little puff of smoke too . only when yer give it a spank tho.

stew

 

puff of smoke,thats a different story............

 

go on then tell me whats going on?

id assume that as i have no cats the **** from the exhaust isnt geting filterd and is allowed to come streight out. its not possible to see whilst im driving but a few of the local lads see it the other day whilst oi gave it a boot out of a junction. some said it was hard to notice and other said it could of been dust from the road side. so what would you say?

 

Mine used to backfire loads. Full decat and vta dump valve. Inbetween gear changes and when at high revs backing of full throttle. Loved it

But now its been remapped and not running quite so rich it doesnt do it as much

 

thats probly my problem. im using a hks mushroom filter (not oiled) so it shouldnt run too rich? to a degree isnt running rich safer? also its a 93import optimax and millers all the time. scooby ecu going in beginning of next month

 

im also using the stock re-circ dumpvalve

 

black smoke - over fueling
blue smoke- burning oil
white smoke- it wont be white smoke.different times vary but a nicely running car wont have any smoke whatsoever

 

tar. when im re maped it will be sorted

 

the smoke was BLACK stew, so it sounds like over fuleing m8

 

ok