KevinLe

iTrader: (1)

i know for SURE then if we take out the CAT ( all 3) we will have at least 20 more hp, so did anyone did it b4? does the check engine light appear?? and how its gonna effect the engine??
please let me know if someone already replace the CAT with a straight pipe

DaveGS4

iTrader: (2)

Kevin,

Just curious... if you haven't done it or know someone that has, how do you know for SURE? Did you do a before and after dyno?

I'm not sure about TX, but in NC and other states we'd never pass annual inspection with no cats.

KevinLe

iTrader: (1)

1st thing i know its for SURE because with a same car and same engine in my country ( asia) but just without the CAT (only US and some country in Europe require the CAT) and its put out at least 7% more horse
and if u talkin bout emission test, of couse its NOT gonna past, but who care bout that cus if u think about street racing its already eligal so just pay bout $40 for each year to past ur emission test in eligal way too

LXOGOOD

Kevin, there is one important factor you are missing. NOISE LEVEL. If you removed all 3 cats and replaced them with straight pipe, your car will sound very loud and high pitched. Most of us bought our cars for luxury and comfort.

If your car was a just a track car, then I would say go for it. If it's your everyday car, then I say no way. It's not worth the extra noise, failed smog, Check Engine Light, car smelling like fuel because there's nothing to help burn it!...

Last thing.... I highly doubt you will gain 20HP from removing your cats alone. Maybe 5-7 HP if your lucky. A good high flow header system without cats may produce 7-15HP here in the states.