I have a d16y7 with DC Headers, ram intake, as of now crush bent pipe with apexi n1 muffler. I am using a OEM 99-00 si catalytic converter but im redoing my exhaust. My car has been rather week lately and my cat. seems to rattle once i hit like 3000 rpms. Also at idle it seems to be loud and rattling also. Im going to be getting 2.25 mandrel bent piping and i want to replace the cat with a hi flow one. Which should i use and what is everyone else using?
also...
Am i going to feel a difference with mandrel bent pipe verse my crush bent, it also is crushed badly in 2 spots, half the pipe is sealed. Will it flow smoother?

 

Well, you could drive my car and see if you feel a diff (Im in MD). JK man. Anyways, searching would show you that most ppl use the carsound cat, and they have renamed it the 1-year cat. Carsound makes good stuff from what I hear. Most people will either say carsound or new OEM. Dont crush out the honeycomb and dont get a test pipe IMO. Unless you are heavily modded, you wouldnt feel a gain with the loss of that extra backpressure. Right guys?

 

Why are they called that? Do they tend to go bad after a year? Also i figured thats the best cat but which one do i get? They have so many. What are you guys running with y7/y8 H/E combo

 

you won't feel a difference with a madrel bent piping....i'd be suprized if you can feel difference with 2 inch, 2.225 inch and 2.5 inch.....

in fact you are probably losing much needed tq with a 2.225 piping

 

I have a test pipe. Every little bit of power helps . One of my friends switched from a hi-flow cat to a test pipe and said he could definantely tell the difference.

 

Dont u get a check engine light with a test pipe. I want to stick with a cat, and i think carsound are good but which one do i get for my setup?

 

http://cgi.ebay.com/ebaymotors...33629

i emailed them, told them my application, and got the 2.25" inlet/outlet with rear 02 bung installed. great customer service, cheap too.

they don't come with the flanges, however. i had my local shop do the flanges/install.

 

yea I get a check engine light. No biggie though. I just resset it every couple of days. Only takes a minute out of my day. Besides I will be getting an obd1 conversion soon which should take care of that problem

 

quick question,... i just changed my exhaust... replacing from the headerback... my CEL light is on, cuz i took out the o2 sensor. does it shorten the lifespan of the sensor, if i get the o2 sensor back where it was? or should i replace it with an obd1 ?
btw, my fuel economy has gone for the *****... and the exhaust fumes gets inside the car.

 

which o2 sensor did you take out? The one in the header or the one in the cat? If you took out the one in the header then you better put it back in or your car will run like ****.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AzCivicCpe &raquo;</TD></TR><TR><TD CLASS="quote">

I noticed a gain.</TD></TR></TABLE>
bOOty dyno??

 

dude u live in st. mary's, we dont have emissions down here, just get a test pipe made. I know a guy in waldorf that will probably make one for u for like $20. He did all my exhaust piping.

 

Landspeedracing.com has very nice Powercore race and street cats. I have the race cat on mine and it was the best exhaust mod I made so far. That is until the turbo goes on If you want a good deal call Matt or Nathan at Land Speed Racing and thay will give you a good deal.

 

Yea i live in st marys but ill be moving to baltimore soon. Where di u go in waldorf for your piping? Did they do mandrel bent, if so how much?

 

Sorry if I was wrong about the test pipe. I have not run one, that is why I didnt back it up. Just from what Ive seen here on H-T, alot of guys have like a religous faith to stop people from running test pipes. Carsound sounds like the way to go IMO.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">which o2 sensor did you take out? The one in the header or the one in the cat? If you took out the one in the header then you better put it back in or your car will run like ****.
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i took out the sensor in the cat. if i get a bung made, and stick the o2 sensor back where it was... is my CEL light gonna come on again?... or