I really need to try this. I have some pretty good rasp that almost sounds like an exhaust leak, but i've had it checked twice by the shop that installed them and everything looks sealed correctly. Probably just the craptastic gaskets that are included. I used the cheap junk gaskets on the exhaust manifold side and the OEM gaskets on the y pipe side.

What y pipe are you going with? Is the rest of the exhaust stock?

 

Anytime you remove a catalytic converter this is going to happen.

 

Good job, Brad! Glad to see you doing something with your car again, and particularly a worthy mod like this.



(psst: motor mounts, motor mounts, motor mounts, LOL)

 

Just those Y pipes you see on Ebay more than likely (in the $150 range), and I have the Top Speed Y back exhaust.

As far as fuel smell, noticed a bit, not much TBH, I was initially overwhelmed by the burning ATF mix that I slathered on the bolts.
The exhaust smell seems to be something I could live with since I rarely am idling in stopped traffic.

 

Ah makes sense. How do you plan on transitioning from the 3" outlet on the ebay Y pipe to your Top Speed Y?

I rarely notice the "raw fuel" smell with the cats being gone when I'm in the car, but it's very noticeable to me when I'm outside the car especially on a cold start. I kinda like it though so doesn't bother me one bit lol.

 

Ewww! Backing my car into the garage every evening would have me and my kids falling over !

 

great write up I ll be attempting this soon! what did you use to take out the o2 sensors and put them back in? a slotted socket?

 

Been thinking about that Y transition, I may take my mid pipe to the shop and have them cut it back where they could weld a small section of 3" pipe and a new flange. I'll probably try it as is first and if it seems like there's a problem I'll do that.

 

I used a box end wrench, once you unplug the connector there's just enough room to slide it over and get to the sensor nut. I then used another box end wrench over one of the sides of the wrench to make more leverage (the hillbilly cheater wrench, lol)

 

awesome thanks brad!


Wasn't sure if I would have enough room to slip the sensor plug through

 

Be sure to keep us posted on this please

 

Any cel light yet?
And is the raw fuel smell due to needing a tune ?

I may add a set of HFC's since you made it look somewhat easy. BUT......I do live in ca and would have to change them out every few years for smog. Now i dont' know again.

 

ahh, the good 'ol days of California smog testing....I remember keeping my stock set of cats and swapping them in every other year for the smog tests when I was running BERK HFC's in my M35. What also helped with the fuel smell was when I ran the Motordyne xyz pipe (ypipe) + HFC module. I'm not sure if MD makes the xyz pipe for the g37 - haven't visited the site or talked with Tony in a long while, but that would be ideal.

 

Once you get them changed out be SURE to apply copper based anti seize to all exhaust bolts, this will make any future work much easier. If it were a yearly swap I'd say no, but 3+ years I would for sure do it

As far as the raw fuel, it's not overwhelming, at least standing behind the car in the garage (standing outside). I doubt I'd want to be backing into my garage on a regular basis though. And yes, the fuel odor is to be expected w/ test pipes since there's no catalyst in the exhaust stream to break down most of the emissions.


MD does make the xyz pipes for Gs that come w/ just the pipes, a resonated chamber, or the catted resonated chamber. Pretty slick setup that I think starts at about $400 and goes up to $550 range IIRC.

Got my G cleaned up today w/ a few more spirited rasp-free, CEL-free runs, should get a sound/vid clip tomorrow.

 

I need to try the RTV + gasket combo. How much did you torque down your exhaust bolts, especially the HFC ones?