Hi folks! I bought a used 03 OZ Rally in December. I absolutely love my car, and have been lurking in these forums for awhile before signing up. I bought the car from a dealer, and he made the comment that the guy that owned the car before me did a few things to it, but didnt void the warranty. So i did some poking around under the hood, and saw that he put an AEM CAI on. He also did somthing to the exhaust, but I am not sure how much he did. He certainly put a new muffler on it, but I was thinking about putting RRMs Highflow Cat on there. I looked under the car, and there is only 1 CAT on there now, and I thought I read in a thread that there are 2 stock. So my question is, how do I determine if there is already a highflow CAT on there? Im still relatively new to tuning, and any advice would be a great help. I can also post pictures if that is needed. Thanks guys!!

 

post pics...

 

OK, here is the pic of the CAT that is on there now. Best I could do at the moment. There is only pipe after this until the muffler. Hope this helps..Thanks I appreciate it!!

 

The first cat is part of the exhaust manifold system. The second is under the car and thats the one you replace with a high Flow Cat. If you were to get a set of headers it eliminates the first Cat (which will usually throw a CEL without the eliminator). I'd say first step is done (intake), next find out exactly what he did for exhaust and improve upon it if its just a muff. Get a catback. I think theres a group buy on the Magnaflow cat back right now (which i didnt realize and paid retail for from RRM , but oh well). Once you open up the intake and exhaust then you can start on other things like the headers, high flow cat, maybe the RRM piggy back or if you're feeling daring pick up a wideband o2 sensor and either custom tune with an SAFC or make your own maps with the RRM piggy. You're only limited to your cashflow and your desire to fix things when they break. Good luck and welcome to the addiction

 

Yeah, that's the cat you are going to replace, the other one, like sick311 said, is part of the exhaust manifold.

Ha, I just noticed you are from the Chicagoland area. Which suburb you from? I used to live in Lombard and Gurnee.

 

Thanks for the help guys! I would like to clarify one thing before I investigate that group buy. Since I have a CAI and a larger muffler, is it safe to upgrade the CAT under the car to a highflow, or is there a step that I should be doing first? (ie, headers, throttleback etc?)


I live in the Naperville, Bolingbrook area. My wife works in Lombard!

 

Uh, are you planning on turbo? I have since changed my mind of saving for an Evo and just deciding to turbo. The way I look at it, if you are going to do little bits at a time, start with everything but the exhaust. Meaning go and start with a bored throttle body or something that isn't part of the exhaust system. The only reason I say this is because alot of people say that they lose significant back pressure when modding the exhaust system too much, and the rest of the motor not enough. This way if you are planning on turbo you can have little gains in the form of various bolt ons, while on your way to the turbo, without greatly sacrificing performance.

I don't know if that really made any sense since I kinda tried to throw it together from what I gathered from previous threads. Just my personal opinion. Oh and if you are planning to go turbo anyway, I don't think you would want a high flow cat, I think you would more likely prefer a test pipe since you wouldn't really need too much back pressure with the turbo.

I know that area a little bit, I think I have a distant cousin that lives over there haha.

 

As long as you keep the exhaust mods within reason and dont go crazy the losses are minimal and mainly on the low end. Like said, if you are planning on eventually going turbo then its worth it in the long run to do full exhaust (with maybe the exception of a header unless you are going to purchase the RRM turbo kit). I wouldnt go with anything over 2.25 diameter though because then you will definately lose some power from backpressure. However with mild modding such as intake, piggy back or custom tune, and some things here or there under the engine a catback/cat/header combo should help out a good deal, IMO the loss of a little low end is made up for in the high end, and then again you can always do a little tuning to make the loss minimal. Good luck

 

there's a magnaflow catback group buy? ... i cant find it

 

I couldnt find the group buy either. Looks like there was a sale in Jan, but I missed it I dont plan on going turbo, because in a couple of years I am going to convince the wife that I absolutely have to have an EVO. SO I am gonna keep it NA, but want to get the most out of it. I just ordered the aluminum crank pulley, and plan on doin headers, throttle back, piggyback and tuning down the road. I really appreciate your help guys, this is a great community!

 

I could have sworn i saw one. Oh well, maybe i was just hallucinating staring at my computer all day at work My catback should be here either tomorrow or friday (fingers crossed), intercooler next week, piping later next week, hopefully i can get the exhaust installed this weekend, and then have the intercooler and piping mocked up before i order the turbo