first engine mod on my 2

[nepopolus]

yesterday i just purchased a stone mountain header system for my 5sfe, i also purchased a apexi n1 exhaust system now why i made this thread was to say i am also going to fabricate a straight pipe system from my headers to my exhaust, (dont worry i dont have emissions anymore) i was wondering are there 2 cats on a mr2 or is there a pre cat then a normal one (the normal one i am going to take off but if the other is a pre-cat it is staying on) and btw i will try to make a sound clip as soon as i get it all on my car

[Gairloch]

Any chance you'll be getting g-tech or dyno data before you put these mods on? I'd be very interested to see how much of a difference it actually makes.

There is 2 cats on Cali cars and 1 for everywhere else.

[nepopolus]

eh i dont think so i may dyno the car afterwords but that is about it

[mr2rider91]

yes there is a precat in the manifold which you will eliminate with the header and then there is your main cat witch you will eliminate with that straight pipe

[nepopolus]

sweet,...the only thing is my freind is saying my precat helps my car start in winter is this true ? (though it may not matter i am probly going to get a winter car now)

[Piddy]

^ I've never had any problem with my car starting in the winter with no cats. That sounds like jibber jabber if you ask me. Could be true though. As far as I know the cat really doesn't do anything until it is up to temperature.

[nepopolus]

OMG lol.....i am driving my car with only my racing headers right now OMG it is so loud it is hillarious...camry engines have never sounded soo badass...

[rocketracing]

I drove my NA MR2 all winter with a gutted cat without a problem...

[tamalpro]

i had a 5s in a celica, and i got the cats away and the rpms bounce a little, thats because you need a litle of back preasure, but i never had any problems

[selba5]

Before you leave your precats in place you might want to check out this thread : http://www.mr2roc.org/phpBB2/viewtopic.php?t=11393
Just bought a 2001 mr2 -- read this and got those suckers out post-haste.