Test Pipes, anyone?
Senior Citizen
Joined: Jun 2008
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From: Los Angeles
Most mods we do to our cars are illegal. Most intakes, most exhausts, have your tires slightly stick outside the width of the car and no mudflaps? Illegal as well. I hate every time the topic of test pipes comes up and someone always has to complain that they're illegal, yet they run HFC, which are illegal too.
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Joined: Dec 2015
Posts: 94
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From: Providence, RI
I guess I’m one of those who complain that that test pipes are illegal, but I do not run HFC’s either. And it’s not my fault that this topic gets under someone’s skin. I recall that in another forum threads on test pipes were banned. Of course it will never happen here, but I would like to see it.
To that end... I was very concerned about getting a CEL with my FI RHFC's. Turned out to be unfounded. Almost two years later, and not a single problem.
However, I will point out a design consideration about FI products that's worth noting. FI doesn't support the connecting bracket that runs from each cat and connects to the underside of the transmission with rubber bushings. Without this bracket, there's a fair amount of noticeable vibration going on. Here's a thread I created last year on the topic. It didn't get much conversation, but there's info there, and pictures:
https://www.myg37.com/forums/g37-sed...tions-hfc.html
However, I will point out a design consideration about FI products that's worth noting. FI doesn't support the connecting bracket that runs from each cat and connects to the underside of the transmission with rubber bushings. Without this bracket, there's a fair amount of noticeable vibration going on. Here's a thread I created last year on the topic. It didn't get much conversation, but there's info there, and pictures:
https://www.myg37.com/forums/g37-sed...tions-hfc.html
Last edited by blnewt; Jan 22, 2016 at 01:01 AM.
I just had my berks non resonated TP's put in monday. Driving normally, you can't even tell it has TP's. Maybe the car is a bit louder. But if i get on the gas there is a ton of rasp around 2.5k rpm all the way through about 3.5k. But after that it's more just overall loudness. I have had no CEL light, yet... And I don't care about the smell because all my friends have been catless ever since we started to mod our cars. So im used to the global warming smell. Personally, after my experience with my non resonated berks, I would only recommend HFC or something resonated for sure. But I've had people rev my car and do fly-bys while driving my car, the noise is alot worse inside the cabin than out.
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Joined: Jan 2016
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The fact that you bought a modded and tuned car scares me. I say this because I'm in car business and know how these situations turn out. But I wish you goodluck!
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Joined: Dec 2015
Posts: 94
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From: Providence, RI
Registered User
Joined: Jan 2016
Posts: 30
Likes: 1
na i know the whole history to the car dude put like 8k miles on it and hes the second owner. He bought it to build as a hobby. barely drove it and everything was done at a well known performance shop with documents. I think after he swapped out the stock exhaust to pass ins and swapped it back he didnt want to go through with it again. When i bought it the sticker was expired for months kid put all his $ and in it but never actually enjoyed it. I guess the "modding" was his only enjoyment therefor i bought it and enjoyed it for him
Everyone seems to have different outcomes, best bet is to extend it as much as possible so I would get the elbows and if that doesn't work, you can always clear the code and add extenders too.
I'm sure at some point it would start to but I can only assume it would take a huge difference. My reasoning is because it has to be within a certain range at all times, it would read a ton less at idle and even less at idle at higher elevations, no idea on the exacts though. Even THEN, were talking without any cats at all, I can only imagine how lengthy it would have to be to start reading even less than a cat'd exhaust.
Test Pipes, anyone?
Right but at idle and higher elevations the ECU also read a map sensor crank sensor air water temp sensors and other things. It also reads the O2 sensor along with the other sensors but in a case where it is too far from the exhaust stream in combination with everything else being correct I would be afraid the ECU would compensate and run too rich because it'll read too lean but you're right there is a very narrow area which the afr's are able to be read from a narrow band O2 sensor.
Yeah, frys my brain trying to think of all the what if's lol.. I'd grab high flow cats and be done. The hp gain from straight pipes to high flow cats are very minimal, not to mention you're saving on your carbon footprint quite a bit more..
Yeah I was trying to save a couple bucks because I've done so much into the brakes and the exhaust that I ended up buying a test pipes with resonators I probably should have gone with those Kinetix