which should i go with high flow cats or test pipes? i dont want a check engine light or a insanely loud sound.....im going with stillen exhaust and stillen headers, but dont know if i should go with h/f cats or test pipes? help '!!!!!!!!!!!!!!1

 

I have a stillen exhaust and headers. Good choice

Test pipes or race pipes, are just that - pipes. It connects the headers or exhaust manofold directly to the exhaust. Most come with O2 sensor hookup so you won't get a light. You get more power out of them than you would cats but you get an extremely annoying rasp between 3k and 4k RPM. They run around 200. You will not pass a smog inspection with them. There is also some race pipes with built in resonators to kill the rasp that run close to 400.

High flow cats, again, just what it sounds like. They are catelitic converters that allow a better flow of air through them than conventional cats. They cost around 400+, depending on the brand.

If you can live with a rasp go with the test pipes, but be warned that unless you know somone, you won't pass smog inspections. High flow cats will cost more but you will pass inpections with them.

What I did was install race pipes and then welded on some resonators to kill the rasp. Cheaper and effective

 

Test pipes will also give off a raw fuel smell since there is no cat to do its job. Thats what Jason at Performance told me. I went with the R/T cats since They are the highest flowing. As for the rasp, I only have rasp when the pipes are cold. Also, Test pipes may give you a check light.

 

not true

 

test pipes MAY give a CEL, if the sensors get damaged during install (as could the h/f cats, i guess)

i sold my helix TP's and got crawford h/f's instead... the raw feul smell, black smoke, and VERY loud rasp sound was too much for my taste......

perhaps i resonator (or two) could help this some, but i didnt wanna find out...

eS

ps- no CEL came on for the short drive i took with them on (helix)

 

test pipes wont give you CEL..
damaged sensors will

what do you mean by black smoke ? when did it occur ?