I have a 92 si hb and I have no air care or anything like that for at least 8 hours from where I live so is there any side effects of removing my CAT?

I have a Ractive Intake and an OBX ReaR mUFFLER and everything else is all stock like new. I heard the valves need the Cat for some reason and that it makes the car run alot differnt if you remove the Cat.

Any help is great

THANKS

 

Your car will be louder and smellier, but other than that nothing will go wrong.

Honestly though, you won't gain any horsepower unless your cat is clogged up. Probably not even worth your time.

 

You will notice a loss in torque, but increase in Hp. You will only notice the Hp on the freeway, you 70 to 120 mph will be better. But pretty much pointless to do. But if you remove it, and run some straight pipe out to a muffler it will sound nice

 

The reason it runs different is because is reduces back pressure, which does build HP, but engines need certain amounts of back pressure in order to run effciently.

 

Your idle won't be as smooth, and decellerating will feel realllllly weird. I run a racing cat, sometimes, and notice that to be a major problem. Like was said though, you don't gain anything from removing it (I run the racing cat on the track because it's the only thing non-custom that fits my 2.5" collector) and if you do run it, it's really good for the environment. Your engine will also run better with it in, as your ecm will run closed loop, instead of dumping fuel because it thinks your O2 sensor is shot.

 

Removing the cat will improve exhaust flow.

However the engine only needs so much exhaust flow capacity before it starts to not make any more power from increased flow. Might as well keep a cat.

Your stock cat however, probably is clogged up from being so old. You should replace it with a high flow unit. Practically speaking, it'll make just as much power as not having a cat, and you won't be spewing raw exhaust into the atmosphere.

 

sure its safe, but is it legal? :P

removing a cat can really free things up as far as restriction. what good is your 2.5" exhaust on a bottlenecking cat? but theres a give and take for this. off the line you might suffer because there is no low end back pressure. but high end will gain because there is a lot less restriction. why get rid of a cat completely? get the best of both worlds with a decent high flow cat. still retains some backpressure but flows a lot better than stocks. just my 1/50th of a dollar

 

But...

A 2.5" exhaust isn't going to help anything on a basically stock D16.