MidnightBlue5.0

I currently have Mac equal length shorty headers with their cat'ed h pipe and mufflers/straight tips. I'm thinking of changing over to their long tubes and their 'off-road' h-pipe. There shouldn't be anything else I need to change correct? What other things should I need to know?

Will my check engine light be on if I get rid of my cats?

saleenpride1986

well, the check engine light shouldn't go on if you have no cats, just make sure to have the little pipe thats connected near the middle of the H-pipe attached. Its an air injection tube or something? At least that's what happened to mine, i had that removed check engine light came on, then i connected it and it was fine.

MidnightBlue5.0

Can anyone offer up anymore info?

Portmaster

Put the O2 sensors in the collector and you should be fine. It's never been and issue with the early models. The later models with 4 O2 sensors had to use Sensor Eliminators on the after cat Ho2's

MidnightBlue5.0

Oh alright, thank you.

Mine only has the 2 O2 sensors at the collector

MidnightBlue5.0

What kind of performance gains will I look at going from shortys with a cat'ed h pipe to long tubes with a catless h pipe? If any at all..

saleenpride1986

13-20 hp gain is what it's claimed from stock to long tube headers, then about 10-15 from stock to o/r h-pipe. will be a slight increase in performance perhaps not the most noticeable, but it will sound quite a bit different. I'd say you'd get around 20 hp +-

86HOGT

I noticed a big sound change going from shorty headers/off road H pipe to Lts and O/R X pipe.

MidnightBlue5.0

Good sound change? Or bad?

86HOGT

Great. I don't think I notice it now so much since it's been installed for 2+ years. More raspy and late model sounding.