Misfire

[stevo-with-the-evo]

Hey guys wondering if you could tell me If fitting a cat back onto a car that was remapped with a decat would cause a miss fire between 1000-2000 rpm on take off or is it summin more serious?

All help appreciated.

 

[sponners]

shouldn't do, any other work been carried out at the same time?


I wouldn't drive it hard though if its been mapped with a decat (assume its just or mot?)

 

[4g638]

If it is an actual misfire and not a turbo stall style pop and bang , it has nothing to do with the cat being fitted, the turbo stall type " misfire " has all to do with it especially if the cat is a normal one and not a sports one or damaged.



Remove spark plugs, check, if they seem ok, regap to 0.55. I assume the car is running around the 370-390 mark. If the gap adjustment solves your problem it is an actual misfire which occured due to other various resons, if not then your cat is creating turbo stall due to excess backpressure and reversion.




Marios

 

[Ozy]

I think it is the cat if it was mapped with a decat I was advised that if I put cat back on mine I should get remap

 

[B6lee]

changing exhaust wont cause a miss fire. you could go from a full catted system to having no exhaust at all and it wont cause miss fire. more likely to be plugs

 

[Ozy]

Thanks Lee I don't know but that's what I was told and if I put an induction kit or dumpvalve they said it wnt run right unless you get it mapped with it on the car but appreciate the advice

 

[B6lee]

To a degree what you are told is correct but when your told it won't run right doesn't mean it will be so bad you'll get misfire.

 

[Ozy]

I c what u mean Lee I always thought thats what they mean tho