Resonated Test Pipe
 

So here in PA, in order to pass the state emmissions , you must have a muffler and something that could be passed as a catalytic converter ( just has to look like one with a place for an O2 sensor post cat). So i was thinking of ways to stay legal but w/o a cat...

1) Hollow out cat
- pros: less restriction, pass inspection
- con: creates turbulence

2) Test pipe
- pros: straight through, no turbulance, major hp gain
-cons: doesnt resemble a cat whatsoever, fail inspection, get pulled over, get car towed and get a hefty fine

3) Replace stock cat with a resonated test pipe,
like... http://cgi.ebay.com/ebaymotors/Nissa...Q5fCarQ5fParts (although this one is non-resonated...)

pros: resembles cat, straight through design, passes inspection, to the cops eye, when it gets dirty, it will resemble a cat... for the most part... major hp gain.
cons: must cut out cat and weld new O2 bungs, drill hole in bottem left side after put on car to allow the expanded air inside the "chamber," as you will, so it doesnt blow a cheap ebay weld.

Anybody's input or personal exp. with a resonated test pipe?

Leave it stock.

Your not going to go any faster.

Your from california where emissions is an issue to the governator... why is your opinion to leave it stock?

And plus... the sound would be a bit deeper and sound better. and its cheaper than an aftermarket exhaust which i cant afford at the moment.

Pros a little more throaty sound, maybe a little HP gain.

Cons, probably gonna get a cel, if the inspection uses a sniffer to test the carbon your going to FAIL!

Best Solution IMHO invest in a quality aftermarket exhaust or switch the cat back and forth between inspections if you have a spare.

im with skeezer ^^ I never heard of having something that "resembles a cat" such as a resonator being able to pass inspection in place of a cat, plus no cat means your CEL will be on, so theres no way around it. Just keep your oem mid pipe and pop that sucker on before inspection, then put the midpipe back on when your done. Thats what I do.

You can also look into getting a midpipe with a high-flow cat if your that set on a midpipe and dont want to spend the 30 minutes (if that) swapping your pipes.

Great question…

Ironically, I am in the middle of this as we speak. I just ordered a hi flow cat and am installing it with my mazdaspeed exhaust.

Don’t know how I feel about it or how it will sound or if it will cause a CEL, but I am going to give it a shot. I put the MS exhaust and MS intake last night and I am currently sitting in my office waiting for the cat to arrive. I might put it on tonight, I might wait till the weekend. In any case, I will put up pics and a vid on the sound since I have looked all through the threads and could find this set up.

Will let you know.

http://www.rx7store.net/product_p/rx...flow%20cat.htm

saw too many people have the rx7store cat fail after a year or so... went catless in california. when it's time to smog i'll be putting my old cat back on, testing, then taking it right back off :)

in order to run a straight pipe, resonated test pipe, or holled cat, if you dont want a cel, get the 18mm spark plug defouler from advanced auto parts, drill a 1/2 in hole through the middle of the top one, screw the hollowed one into the non-drilled one, screw both of those into the second o2 bung, then screw the o2 sensor into the drilled defouler. Make sure all seals are tight and you wont get a cel. I had this done on my 07 civic si for appr. 30k mi with no cel.

This doesn't work on the RX8, and if it does, its only for a few hundred miles. The 02 sensor is always expecting a certain voltage at diff times.. no way to temper that with a non-fouler...

hmm... so the only way is to remove the cel is to get an accessport?

pretty much. if your catless

So why wouldnt a plug defouler work? It still gets signal, but is just backed out of the exhaust... I dont understand...

When I had my speed6 I used a defouler and a diode that I got at radio shack and never once got a cel. Has anyone tried to use the diode on an 8?

im not sure why it doesnt work, thats the extent of my knowledge. I used the defouler with my mazdaspeed protege and it was fine, but other experienced forum members informed that the ecu is too sharp to be fooled by a defouler.

idk about the diode, maybe some other members can chime in...

Im wondering why because i had an 07 Civic Si previously and the ecu has to be just as sharp on it as it is on the 8... I mean it took Hondata 3 years to be able to crack into it to be able to solve the tuning issues everyone was having... i had a defouler on it for 20k without a cel...

The "defouler" as you call it won't work, period.
Why? Here's the answer!

so instead of telling me to search, which i did, why dont you just tell me the answer to the question none of us here besides you know the answer to?

That has to be the most scientific thing ever posted on this forum. Because Honda tried to make it unhackable means it must be super awesome lol. Many people have tried the defouler thing and it doesn't work. Some people have just put a test pipe on with no tricks and managed to never get a CEL (or long periods of time anyway). It's a crap shoot. PS: I doubt you will feel much power difference and the sound with a cheap pipe will be raspyyyyyyyyyy.

and you are going about this the wrong way I think...you are talking about cutting apart a very expensive piece when you can buy the pipe with a resonator already in it? Also what is with drilling a hole in the pipe to relieve pressure? That's some ghetto engineering.

The example i gave was an ebay pipe. And since it was a straight through design with a larger pipe around the straight pipe, and the larger part is welded completely around the straight portion, a hole would have to be drilled in the part around the straight pipe because the heat of the exhaust would cause the air in the "chamber" between the pipes to expand, potentially making it possible to blow a weld. If you would drill a hole in the metal around the straight pipe, then the air could freely expand and and relieve the biult up pressure.

Sorry for the paragraph and run-on sentances...

Pa doesnt have a sniffer test. So i just need something that looks like a cat and has a wire going in post fake cat... PA just requires the vehicle to have something that looks like a cat to be able to pass inspection and to avoid fines.

No one drives the car or wonders about the mysterious check engine light? If you HAVE to go catless without a CEL then bank on getting a Cobb Accessport from Mazdamaniac ($400 I think) and a resonated pipe ($150ish-$500 depending on model).

1) Hollow out cat
- pros: not necessarily, fail.
- con: myth

2) Test pipe
- pros: major hp gain? no.
-cons: you're going to fail with all 3 of your options

3) Replace stock cat with a resonated test pipe,
ebay test pipe..? uhm, yeah. you do that.

Just stick with the stock cat, think of the polar bears.