Bought a header..whats next?

Question

I bought a pacesetter header for my 03 cavalier. I'm currently running 1 7/8" piping from the header back. Should I change everything to 2 1/4", or is it not worth the money? I may remove the cat after inspection, but I've heard it can mess with the O2 sensors and turn the check engine light on. Thanks.

Answer 1

as a former cavalier owner i found that if you upgrade the pipes to what u think will add more air flow your torque will greatly decrease, so unless you are making your car for horsepower then i wouldnt change anything on the backend maybe replace the cat with a highflow one as the other person said, and yes i have also heard it will turn thr o2 sensor on, it you have too much air flow it will sound all gurgally and crappy when u let off the gas but if you like that then hey its your choice. my best advice to ya is do what you think is cool it is your car...

Answer 2

Todays cars usually get worse mileage when the cat is removed, and the lack of a proper back pressure may actually reduce HP/Torque.

Be careful of the claims mfg's make to push their products. In testing of a 911 Porsche, 11 differents sytems on the car actually made a reduction on the dyno. The most power produced was the stock set-up...because the original system was designed for the specific application, just as in your car. Anyone can make a set of headers, but may not stand by the claims.

Good Luck!

Answer 3

Meh, if I were you I'd just leave the rest alone. Especially leave the cat converter in place or at least replace it with a high flow model as totally removing it is detrimental.

However, if you do replace all the exhuast, going with a larger diameter pipe would allow the exhuast gases to flow more freely which could help power. But on a cavalier? I doubt its worth the money.

Answer 4

Never remove your 'cat', the damage to the enviroment, and to your vehicle is NOT worth it, your engine will NOT benefit at all, if fact, it will harm it more, much more than you realise. 'Old school' thinking said that you install larger pipes progressively toward the rear, 'new school' leans to progressively SMALLER pipes. The reasoning here is that as the pipes get smaller, it has the effect of 'speeding up' the exhaust gasses,(same volume, smaller passages) causing them(the exhaust gasses) to exit the pipes quicker, allowing the engine to 'breath' better. I still install slightly larger pipes 'cause' I LOVE the sound of larger pipes( I am old school)!Of course, I am talking about v-8 engines here.

Answer 5

just put the header on and leave the cat alone unless you want to put a high performance cat on it and then maybe go up 1 size in the pipe and put a high flow muffler on it and you will be all set.