Hahah well I was beat on hard I agree. But in the end I will be driving said Z with HFC's down to the metal recycle yard to cash in on my stock cats for some cash... :ughdance:

It's no surprise to me at all actually. I had a bad feeling it was going to be an EPIC fail moment for me. It always is with me. Whenever I do all my mods I take the stated install times and multiply by 4 and throw in a monkey wrench and thats how it ends up. I just accept that and it's all good. ;) It's still better than paying the rediculous install costs! Nissan wanted $450 to install my Nismo S-Tune suspension!

It's all good, man! Dem Debbil bolts have claimed many victims.

:iagree:

+1 rep just for knowing you were going to FAIL and did it yourself anyway!

Great job man! :rock:

I know what you mean, sometimes you just have to just get sh.. done. Just be glad your not a tech and it wasn't a customers car or something, "umm, we had to cut your cat in half,here's your car" lol.

Installed mine without an issue, just had to use extensions for the top flange bolts and a breaker bar. Had them out with Test pipes installed in about an hour. But also used a lift at a co-workers house.


DAN

Man that would of been so nice!!! You have no idea.

HAHA^^^

So Is everyone getting a crazy loud and I mean loud hissing/Whistle/Humming noise on Decel around 3.5k-2.5k?

I also Have aftermarket exhaust installed. I have had a Test Pipe Exhaust combo on my 350Z and didnt have this loud of noise.... Its bad real bad

DAN

Nice power gain, but catback exhaust is all I will ever do on this car. Headers and cats will stay on for good.

^yup...I had no clue the hiss would be this loud! What I'm more upset about is how quiet the HKS and Berk combo is. I guess I was used to the sound of the open y-pipe I ran for 3 weeks and then the open headers I ran for 2 weeks.

get used to it. i did.

Oh the wonderful hiss! One thing that could eliminate that sound is a piggy back system of some form for the ECU. the sound is around2.5-3.5k....program your throtle position sensor just slightly in that RPM range and it will disappear. As far as getting the right piece of equipment to do that, I have no clue...I'm kind of a rip the entire ECU out and replace with standalone kind of person, so I have zero knowledge with the latest piggy back systems...food for thought.

I don't see how... you can't tune exhaust pulses with the ECU :confused: (well, you sort of could if we had control over VVEL...)

Anyway, just got test pipes on, and yes, it hisses a bit.

My buddy who did the install thinks it might be due to the fact the pipes are single walled, and that's just how they vibrate.

Note the big weights on the either bank of the exhaust around the Y-pipe -- this motor just has a lot of weird resonances to work around.

How long before you know for certain you're in the clear for getting a CEL? I've not driven too much yet, but have gone through multiple "trips".

I got one after about 500 miles, then in went the steel wool, drove it 8,000+ CEL free after that.

Lol yeah I get hissing every time I release the throttle except for maybe say 7000ish.

and then that rasp while accelerating.

Hmm. Okay -- thanks. You just wedge a small piece into the bung?

Also. Mine has the long "u" bend defouler, like GTM -- was yours the shorter straight one or also a U?

Your not tuning exhaust pulses, just relieving back pressure, I don't' want to get into detail...wrong thread. I haven't heard anything about single walled pipes or weights on stock exhaust, that is kind of interesting.

As far as your CEL goes, you can get codes at any time....any time! Personally I wouldn't ever use steel wool, just seems like poor mechanics. Not that it is going to cause damage, but your just asking for problems down the road.

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html <this is one of many sites, look around you will find many more

Get some high quality fittings and do it right the first time, you shouldn't have any problems with a high quality fitting for your O2 sensor. If that doesn't work the steel wool might....but your only buying yourself time and I guarantee that it will fail at the worst opportune time.

The CEL is tripped if the ECU detects the same rate of voltage change between the two O2 sensors in either bank -- that is interpreted as an indication that the cat has failed.

All the defouler (or one with steel wool packed inside) does is allow for more distance/block gas flow so that that the rate of change is different. How different they need to be depends on the ECU logic.

Mine has an extra long, U bend defouler, so it should be fine, but if not another defouler to further extend it or the wool to slow things down should work fine.

Feel free to start another thread under tuning or shoot me a PM to explain -- I still don't see how playing with TPS will affect back pressure one way or the other (although taking out the restriction of the cat does that mechanically).

I guess you might be referring to actually commanding more or less throttle opening via VVEL or throttle blade actuator rather than simply having the ECU read from different load cells in it's fueling map. Is that what you mean? You can do that with your foot too...

Anyway, I don't see how that would work because if the resonance is RPM dependent, which is what I think, you still have to cross over that RPM, even if you physically open the throttle more.

It must be a specific resonance issue -- that would explain why some shops offer resonated test pipes to cancel out some of the vibrations. You can't tune that -- or at least I don't understand how -- with an ECU :confused:

I'm not trying to be an *** here -- expertise is relative, so if someone knows something I don't, I'd rather understand it than automatically agree or dismiss it.

I have the Stillen Gen3 installed... will I need to take this apart to get to the bolts with the extension? Please tell me I don't need to take the front fascia off again :)

I just installed my test pipes and have to say that I think everyone is exaggerating the demon bolt. Sure on the drivers side I may have snapped the stud in half, but at least it was easier than the bottom bolt that was closest to the inside of the car. Seriously. WHAT THE #$&#*?!?!?!?!

When I read through all the installs I thought I read there are 2 bolts pointing to the back of the car and 1 pointing into the engine bay. Is that correct? If so, my car was different. 2 pointing to the engine bay and 1 towards the back.

Horrible, and thats coming from someone who had a friend doing almost all the hard work.

I think the location of the Hiss is comming from the X Pipe on my ARK exhaust due to the amount of increased exhaust flow because of the Test pipes, I talked to ARK and they said that is were and how it is happening because they designed the Exhaust with stock cats in mind..... so Im going to sell it and get the HKS with the H pipe it shouldnt be as pronounced then.


DAN

Keep us updated please, I would love to hear the HKS with test pipes too!

I didn't need to remove the intake from the throttle body. There were just enough room to get access to the header/cat bolts.
I have the hiss with the HKS. If you would like, I can post a sound clip for you to see if the hiss is comparable to yours.

Please do! I would like to hear it.

nevermind. I just found the other thread.

Ummm okay, I just got my FI Test Pipes in the mail. I'm getting them installed by a performance shop in the area, but the instructions talk about removing the steering knuckle. Did all you guys have to do this?????

Will do Im installing the HKS Tomorrow!



^^I hope its not as loud as it was with the ARK I mean it was crazy loud, I had hiss on my 350Z with headers/testpipes/Exhaust and it wasnt bad just a little on decel. But with the ARK It sounds like my car is turbo and not the good turbo sound, more like the one were the impeller is siezing haha.

I will post some thoughts on the New HKS compaired to the ARK hiss or any other hiss/Whistle/Howl for that matter


DAN

Question. The bottom of the stocks cats where they bolt to the y-pipe should have three bolts/nuts per side right? My drivers side has two out of three nuts there. The bottom nut is missing. But there doesn't seem to be a lot of threads showing to even put a nut in there.

I bought my car used from a forum member that out the stock exhaust back on. Just wondering if I should have three nuts per side on the bottom part....that's how it is on the 350z.

Yes, each side has three bolts. I figure that over time since you bought it the bolt came loose and might of just fallen off? I would check to see if it has a small exhaust leak, and if it does? Replace the gasket and replace the missing bolt. You can find them at your local auto parts store or a local muffler shop.

I have an extra 350z nut that fits. But it looks like the cat isn't lined up with the header properly and the bolt is çrooked. If I put a nut on the bolt I think it starts to strip the threads. I think I do have an exhaust leak at high rpms maybe. Not sure if I should mess with or replace the stocks cats completel...lol. ill post a pic.

Drivers side
http://i118.photobucket.com/albums/o...1-30121339.jpg
http://i118.photobucket.com/albums/o...1-30121357.jpg

Passenger side
http://i118.photobucket.com/albums/o...1-30121406.jpg

Wow talk about bringing a thread back from the dead haha





DAN

Are the flanges on the stock headers threaded? Or just an open hole like the rest of exhaust?

im pretty sure that one of those three bolts is just a stud with a nut on it..

Yeah, one of the top ones is a stud (you can see that one on the passender side that has a different head on it).

I'm curious if this is okay the way it is? I'm thinking that the lower bolt without a nut is actually theaded into the flange....maybe.

I know that aftermarket it's definitely 3 bolts per side.....but what about stock. I think that bolt might be all that is supposed to be there....without a nut.

Guys one other thing. Does it look like there is even an exhaust gasket in there to you???

If I remember correctly on that side? No
and by the looks of it? there isn't one

Edit. Nevermind...found out on another thread the 370z does not come factory with gaskets between the manifold and cats.