4.8l 2005 cats

heavychevy5speed · July 4, 2012

Can my 4.8l in my 05 run right without cats on it?

Mckenzie · July 4, 2012

Indeed it can. Your check engine light will come on but and you might suffer a slight drop in mpg but your truck can certainly run without cats. You can run no cats on your truck with a spark fouler wich tricks your truck into running as if thinks the cats are still there or you can "tune" them out with a tuner

MikeNH · July 4, 2012

Assuming there isn't an issue with them, there is no reason to remove the cats. You also need to make sure you won't have issues with state vehicle inspections or emissions testing if your state does that.

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Prokopchuk_9 · July 4, 2012

ya dont take them off until you have too, the best way is shutting down the downstream 02's with EFI tuning..you will lose low end torque but gain top end hp. not worth it IMO, i knocked the guts outta mine didnt really make much of a difference...

heavychevy5speed · July 5, 2012

The truck has 253xxx miles and factory cats i had knock sensors all four o2 sensor codes and a mass air meter code and i have been told it was because of my cats being stopped up and anything after about 3 grand in rpms i have no power wats so ever. I have minimal exhaust pressure

Prokopchuk_9 · July 5, 2012

Ya it's the cats...you can knock em out its a bit of work tho

heavychevy5speed · July 5, 2012

Okay thank you. Cause its a pain to have no power

Doug_Scott · July 7, 2012

The truck has 253xxx miles and factory cats i had knock sensors all four o2 sensor codes and a mass air meter code and i have been told it was because of my cats being stopped up and anything after about 3 grand in rpms i have no power wats so ever. I have minimal exhaust pressure

Not sure if you mean what you said, or not. If you have minimal exhaust pressure, do you mean you have little/no flow out the tailpipe, or that you have little or no pressure in the entire exhaust system? To check if the convertors are plugged or are not flowing correctly, drop the exhaust and take it for a drive.

No power under load can also be a plugged fuel filter, and it behaves just like a plugged convertor.