Just curious, if I'm going to be getting the downpipe, I don't want it to be stupid loud. Now, from everything I've read, the downpipe is the pipe that starts pretty much from where your exhaust piping starts running under your car from the front axle up to the back axle. So, the downpipe gets rid of three things:

1. Cat converter
2. Resonator
3. Restrictive piping

1. Ok, so if I find the thing so loud and want something thats nice to the environment on emissions and get a high-flow cat welded on, I'll be losing the advantage of removing the cat. Not to sure how much horse I lose because of this...

2. Doesn't the resonator also control noise? So if the thing is super loud, won't I need to weld on a new resonator? Does that result in a loss of power?

3. Restrictive piping. Looks to be the only benefit I would get from the downpipe. So I'm really curious to know how much gain is to be had from this mod. Anyone in the know with an answer, it would be greatly appreciated.

If I'm completely off the wall here, please point out my misconceptions.

Thanks a bunch!

 

The Downpipe goes from the Header of the car to the Mid pipe...
So that takes out your catalytic converter, but DOES NOT remove the stock resonator... The Hi-Flow cat should work on both sound & emissions...

You shouldn't hinder the gains by welding in a hi-flow cat because this downpipe from RRM removes the stock pipe which has a very NASTY kink in it and is not shaped for good free-flow...

Check it out:
https://www.evolutionm.net/forums/sh...d.php?t=138691

Hope this clears some of this up!!!

 

so if you weld in a high flow cat after the DP, you will:

a) reduce the noise a bit and,
b) ensure that the CEL doesn't come on

is this correct?

Cheers,
Ry

 

Correct.

 

so how come people don't just put in the high flow cat then? seems like a no brainer, but maybe i'm missing something...

 

Money and hassle. $5 fixes the CEL problem. Down in the states, many shops won't touch your exhaust after you remove the cat, so it's not so easy to get work done. Personally, I gave up. There are performance/tuner shops that I'm sure would happily do it, but there aren't any near where I live. I've just learned to live with the volume, it's not that bad.

 

I wasn't going to until my CEL started being stubborn and wouldn't go off... Otherwise I wouldn't be doing this!!!

 

ahh. to me i think i'd rather spend the extra cash to put in the HF cat and not have the cel on. that way, if it does come on, i'll know that it's cause of something else legitimate, and not just the dp causing codes. if my cel comes on with the HF cat on there, then i know there's a problem and that it's not (in all likelyhood) the DP causing the cel.

 

I've got 2,000 miles on my downpipe and no CEL by using the defouler mod

 

oh, and i'm still not sure what a defouler is. like, is this something that you get at an auto store or...i have no idea. is there a link to what one is online somewhere? this defouler thing is all greek to me hahahah

 

https://www.evolutionm.net/forums/sh...ad.php?t=99137

That's the defoulers... They are available at a local auto store... It's cheap...
You should be able to find them anyhwere... They are HELP! brand spark plug anti-foulers....

 

After my CEL fix, my light has come on 3 times, but has always turned off by itself within 2 days. I almost 10,000 miles on it.

By the way, to the guy above, YES it is stupid loud IMO without a resonator!!!