a newbie question here. i have a z32 na automatic and i have a bit of an exhaust issue. will it better to replace it with straight pipes or whole catback system?

 

"Better" is relative.

Will the car need a yearly emissions check?

 

yes im looking for better and no yearly emissions test.

 

A "cat back" is just some pipes and a high flow muffler bent in ways to reduce exhaust back pressure.

straight pipes usually means you get rid of the cat and muffler entirely because other than burning up the bad stuff and muffling the noise that would come out of your tailpipe, a cat and muffler only restrict your exhaust flow. So you would have only pipes fro your headers back

i dont know about other states but you can be ticketed for running your car on the street without a cat in California. And you'll fail every smog check you ever take.... oh yeah and the car will be freaking LOUD!

personally i interpret better as a street legal cat, and whatever combination of pipes and muffler you think make your car sound best.

not sure what you mean by better but if you mean performance. you wont be able to tell the difference between any of the options aside from sound really.

lots of companies boast better mpg and more horsepower but they measue this under factory conditions and only boast of gains up to 10 hp or 5 mpg really and you will be luck if you get half that. wont change your track times or your wallet size.

 

Will straight piping in place of the converters cause a check engine light

 

NA car, probably want at least a good muffler 2 In/Out or dual mufflers and no cats or test pipe so it still looks legit if in question.

 

On an OBDII car (96+), yes it will pop the CEL... in which case it will not pass emissions. On pre-96 cars, RARELY will a car pass the tailpipe emissions test without a cat. You need test pipes so you can re-install the cats for emissions testing as Turboboxer6spd mentioned.