mwilson

So I just got my magna flow exhaust with K&N intake! Sounds super clean! But.....the shop said they did not want to install HFCs or Test pipes because they are afraid my engine light will go off! I need some help on deciding what HFCs will best fit my set up and what headers I should purchase as well! And finally will my engine light truly come on if I install these parts!

GoFightNguyen

iTrader: (14)

As far as I know, K&N only makes a short ram style intake. Your shop is being conservative in their assessment. The only way they can 100% guarantee you will remain check engine light (CEL) free is if they leave the stock cats on there.

However, there are many, many, many, many....many, threads and members here that have high flow cats, test pipes, etc, that do not have CEL's. Simply put, if the cat replacement is designed correctly, i.e. the O2 sensor is not directly in the exhaust stream, then you 99% probably won't get a CEL.

Test pipes have a higher likelihood of throwing CEL's since they inherently have less filtering and processing, but there are steps that can mitigate that. The question of headers is a complex one. I just finished a rather long discussion on a thread about them, you can find it with a simple search. Basically, headers don't make *great* power on this platform given the fact that you already have engineered short tube headers standard. People have them, like them, and get some horsepower boost, but they are a gigantic Pain in the *** to install.

Again, you can find much more detailed and satisfying answers by searching and reading through the dedicated threads for this.

GoFightNguyen

iTrader: (14)

After a quick search, here are some links I turned up.

https://www.myg37.com/forums/intake-...k-exhaust.html

https://www.myg37.com/forums/engine-...s-is-here.html

https://www.myg37.com/forums/intake-...ions-help.html

mwilson

Thanks for the help! I have read many threads about headers and everyones saying just stick with stock and what not so I will most likely do that! But the HFCs are the biggest problem! What im most likely gonna do now that I know i shouldn't get headers is that on my tune,when installed, Ill do my HFCs just so I do not get a light! What do you think about that? And also one more question! What do you think about Berk HFCs? And should i go with another brand??

GoFightNguyen

iTrader: (14)

I want to go on the record as saying I didn't say you "shouldn't get them."

I wanted to say that "most people don't get them" because the power increase vs price isn't usually worth it.

Test pipes probably won't throw a light either, but they WILL cause your exhaust to smell and be louder than most people find comfortable. I thought about it, and I stand by my decision not to go TP's.

I haven't had Berk HFC's personally, so I cannot speak from experience. However, I have heard rumors that they have a tendency to spit the catalytic matrix out and become test pipes anyways. I have Fast Intentions non-resonated high flow cats and I love them, if that helps.

Tommy Gunz PSIU

iTrader: (1)

I guess I can chime in . I have Berks, and they are great. My only issue with them is that the core is slightly loose in the chamber of the HFC. So basically on a cold start up, the core rattles around in the chamber. Once the car is at operating temp, the core expands slightly, and it no longer rattles. This explanation was confirmed from someone at Berks. I'm assuming this rattle is what may cause the core to eventually break down and get spit out the exhaust (like Nguyen mentioned).

Just an FYI for the OP. If your mechanic is saying they wont install the HFCs because it might throw a CEL, then i would definately not try and get used HFCs installed there (i wasnt sure if you were buying new or not). I bought used, and in some places, it is actually illegal for a shop to install used cats. My mechanic wouldnt do it, so i had to drive my car about a mile back home with the cat delete mod so i could install them myself. A pointer for anyone who wants thier car to sound like a monster truck... just take your cats out.

Anyways, I like the Berks, i plan on getting an Ark cat back, because I've heard it before and I love the sound of the two put together. Just my two cents

Tommy Gunz PSIU

iTrader: (1)

Oh, and i also meant to mention. There was a thread on here about HFCs and either the Berks rep, or the Fast Intentions rep chimed in with stats about percentages of HFC vs TP that throw CELs. I dont feel like looking for it, but Its somewhere on here.

Onecleana55G

I have Top Speed Pro1 test pipes with the O2 extensions I also removed my stock resonators and installed a Top Speed Pro1 axle back exhaust, start up and idle AMAZING sound but if the test pipes aren't warmed up and you accelerate hard it will rasp. After the TP's heat up from a bit of driving the sound is intoxicating, sounds like a straight piped GTR, always get compliments on my G and do not regret the setup I'm using, very happy with it also no CEL for over 6 months now, I have Injen SRI with a Uprev tune if that helps, however I did get a exhaust ticket in Virgina the cop said he heard my car 3 car lengths away with his windows up lol 100 dollar ticket and no problems so far with cops, just keep a look out and shift up. Would never do headers because it is a pain to install plus I feel like the exhaust will be to loud. Just my 2 cents

warped ideas

Glad to hear that the cold start-up RASP isn't just with my Kinetix HFC's. I feel better about them now.

To the OP, I just installed my HFC's two weeks ago (NOT A SINGLE ISSUE) and I love the way they make the engine sound. I posted a video and review on the mod, so if you want to read on it then watch the video click this link.

https://www.myg37.com/forums/g37-sed...nd-review.html