Well I just finished up my first test pipe / high flow cat install. We reached a couple points and figured we should take a pic to help people figure out how to get the top bolt off of the stock cats. Enjoy:

1) Lots of extentions are a must:



2) Here are the Helix test pipes:



3) Here are the New Helix High Flow Cats



4) Here is a picture of amf813 looking all pretty not getting under the car or getting dirty while me and a buddy do the work:



5) Here is a buddy and my fat *** with the tool pictured in pic 1 on the top cat bolt about to take it off, we used a breaker bar before switching to the air ratchet. You get the other one off the same way, just snake it down there:



Let me know if you have any questions. We didn't have time to do my high flow cats just amf813's test pipes, so we do mine tommorow before the Super Bowl.

 

I was the task lighting expert in charge of holding the flash light, which is very important when you do work like this at night.
The test pipes sound awesome, thanks for your help Tut!

 

No problem man. I will try and take more pics when I put on my high flow cats.

 

You know, it IS possible to get at that one nut from under the car with an air ratchet. Whether or not its easier, i can't say, cuz that was my only option...i didn't have the extender.
Oh shzit, i just noticed you connected a bunch of shorter extenders together...brilliant, i never thought of that. Was it a bzitch using that approach?

 

hahaha that's a lot of extensions. i thought of doing it that way but was like one extension too short. so i ended up doing it all from underneath the car. i bet those bolts are way easier to get off and on from the top though.

 

I didn't see any way to do it from below and figured Nissan meant for that top one to be gotten from up top. I mean you can't even see the nut from underneath the car. The Helix products were nice too cause they came with all new hardware that made reinstall really easy, but I know the high flow cats will be harder due to how close the catalyst is to the flange.

 

I'm interested in hearing a video of the Helix HF cats when you get them installed (and after the superbowl I imagine, ).

 

The installs really are tough to do. Go buy an extension kit for the top bolt. The stock cats are easy to remove and install since the studs are welded in. If you buy some HF cats/test pipes I suggest welding those 2 bolts like stock. If done you can install yourself without assistance or air tools, but it's still not physically easy to install.
Cat to Header torque: ~45ft-lbs
Cat to Y-pipe torque: ~40ft-lbs
Enjoy.

 

I didn't even think about torque specs. I might go back out and do those while the car is in the air. Anyways, NEW PICS are coming right up.

 

6) Comparison of Stock versus Helix cats



7) Comparison of Stock versus Helix cats



8) Comparison of Stock versus Helix cats



9) Comparison of Stock versus Helix cats



10) Inside top part of Helix cats



11) Inside bottom part of Helix cats



12) Inside top part of Stock cats



13) Inside bottom part of Stock cats



14) Passenger side cat



15) Passenger side cat



16) Driver side cat



17) Driver side cat



18) Passenger side manifold flange



19) Driver side manifold flange



20) O2 Sensor Hookups on Tranny

 

Nice pics, and informative write -up.

Any sound impressions of it with your Injen exhaust?

I was thinking about the helix, but worry about the drone =/

ravi

 

That's a great write up! I have a set of Helix test pipes sitting in my closet at home. For the life of me, I couldn't find an exhaust shop that wanted to install them. I had to wind up going with some RT cats, but I'd still like to get those Helix installed.

Ian

 

I really didn't notice a difference in sound on the test drive. I did, however, notice a little rattle. I think the driver side one has some clearance issues when the motor is vibrating a lot like at idle. I'm going to jack the car up again next weekend and see what can be done. I will try and get a sound video next weekend as well.

 

Keep an eye on the bolts that connect the pipes to the headers. Mine backed off pretty quickly and I didn't even realize it. We noticed it when I got the car inspected.

 

My car has a noticeable rattle as well now. We definitely need to check the bolts again next weekend.
Oh, and by SES light came on today..........

 

Your rattle is definitely not from the test pipes hitting anything cause there was plenty of clearance there and I am sure the bolts are tight, but we can check them again. Plus the noise was from the back of the car. I think it is just the resonance of the exhaust causing everything in the back of the car to vibrate. I would try the Technosquare instructions for resetting the ECU to get rid of the SES light.

 

i agree.

john

 

i can definitely see how the helix cats could have fitment problems up near the header cuz they are so fat up there; the stocks get fat more gradually. My kinetix cats weren't even that big, and they required some creative fitment, ie, hammer and chisel to underbody. my kinetix tpipes were easy cuz they're lots thinner up top.

 

Not sure about the differences among the test pipes v. cats (Helix), but I just installed my Helix test pipes with my new Y pipe (then connected to the RSr exhaust) and had to do a minor modification to keep the Y pipe flange from vibrating against the underside of the vehicle.

On a similar note, does anyone have an obnoxious (loud) rattling noise coming from the rear passenger quarter window? It started last year (possibly due to the interior being taken apart for custom audio) and I've been too lazy to check into it. Once I installed all my new pipes, the resonance makes it a lot more pronounced! It sounds like a metal bolt vibrating against the plastic or maybe even the metal . . .

G

 

Nice write up! Had mine installed as well the next day I got it (Friday). The shop I took it to did make some slight modifications for fitment/rattle issues. They said it looks fine when you first install them but once you start your engine up, it will rattle enough to slightly hit a portion of the car. After they did that, no more rattle. Not sure though if this is the same as what you guys were hearing. As far as the sound goes, it sounds fairly the same until you pounce on the gas. Then it'll sound like a totally different beast . At least, that is how it sounds like with my Fujitsubo setup. I do, however, noticed some droning at the higher rpm range when I attended a meet/drive in my area. But then again, we were WOT'ing everywhere . Overall review, I'd say it's a good mod with a noticable increase in HP/TQ. Sound is not intrusive depending on what exhaust setup you have.