DIY: Stock Catback Exhaust Removal
 

Couldn't find one of these anywhere (probably because it is so simple :) ) so figured I would write one up since I just did this as part of my HKS Hi-Power Titanium Exhaust install.

Tools Required
14mm socket (9/16" is close enough)
12mm socket (1/2" is close enough)
Ratchet Wrench (I used a 1/2" but 3/8" might work fine)
Penetrating Oil depending on age/miles or strength :rofl2:
Armor-All (you'll see)
Jack and Stands

Step 1
First thing is to get the car on a nice level surface and jack up the rear then support with adequate stands (unless you have a lift handy which would make all of this much easier on you).

Step 2
Next up is to loosen the four 14mm bolts holding the Y-Pipe to the stock cats - these are only torqued to about 40 ft-lbs so it shouldn't take too much effort - if things look bad down there you might try some Liquid Wrench Penetrating Oil or Aerokroil.

http://www.the370z.com/members/linpa...ection-cat.jpg

http://www.the370z.com/members/linpa...onnect-cat.jpg

Step 3
After that loosen the two 14mm bolts holding the Y-Pipe to the mid-section - this one was a little tight getting the socket in there - I had to use a lower profile socket instead of a deep one or you could fish an extension over the center bracing to reach it if you had to.

http://www.the370z.com/members/linpa...k-mid-pipe.jpg

Step 4
Then loosen the four 14mm bolts holding the muffler to the mid-section - one side note, I simply can't believe how rusty the flanges are on this: the car is less than a year old and only has 2,800 miles on it - to have that much rust just seems unacceptable.

http://www.the370z.com/members/linpa...ck-muffler.jpg

Once I knew that I had all the bolts loose, I then worked from the muffler forward to take everything off - I read a post on here that said the installer found it easier to actually remove the supporting brackets and then take the rubber braces off rather than try to yank the pieces out while the braces were still on the car - since I was going to be installing a new setup I decided to follow these guidelines because they made the most sense to me.

Step 5
So, first up was to completely remove the 4 bolts holding the muffler to the mid-section that you loosened above in Step 4. Then you need to remove the three 12mm bolts holding the left bracket on, the three 12mm bolts holding the right bracket on, and the one 12mm bolt holding the left-rear section of the muffler. These are all shown in the pics below.

http://www.the370z.com/members/linpa...-support-1.jpg

http://www.the370z.com/members/linpa...-support-2.jpg

http://www.the370z.com/members/linpa...-support-3.jpg

Nothing really just dropped off once things were removed, I had to wiggle the muffler a bit to get it to drop down - this is the heaviest piece of the stock setup but can easily be handled by one person. Should look something like this once you get it off.

http://www.the370z.com/members/linpa...ffler-tips.jpg

I then used Armor-All to spray on the supports to get the rubber to slide right off - great for keeping those pieces in good condition.

http://www.the370z.com/members/linpa...er-support.jpg

Step 6
The mid-section is also supported like the muffler by two brackets held on with 12mm bolts.

http://www.the370z.com/members/linpa...-support-1.jpg

http://www.the370z.com/members/linpa...-support-2.jpg

Remove these and the 2 bolts loosened above in Step 3 so that you can pull the mid-section out to get this.

http://www.the370z.com/members/linpa...id-section.jpg

Step 7
The Y-Pipe has no such supports so simply remove the 4 bolts loosened before in Step 2 and it should come right off like this.

http://www.the370z.com/members/linpa...ock-y-pipe.jpg

Summary
That's pretty much it as far as removing the stock CBE - putting on a new one is fairly easy - you just start at the cats and work your way back to the mufflers - I basically installed the new setup with bolts hand-tightened and then gradually tightened each joint to the recommended 40 to 45 ft-lbs. Overall, this was one of the easiest mods I've done myself - none of the bolts are difficult to get to and they are not torqued to Herculean levels.

Hope you found this DIY helpful - please let me know if anything needs clarification or correction. Thanks!

LinPark, this will be helpful to those new to exhaust removal world. The pics are very clear and helpful.

I agree with you that the Y pipe bolts were the worst (in terms of effort) to remove.

:icon18:
You guys make it sound easy. In heading to advance auto for some tools. I couldnt get any bolts to budge and I'm a decent sized guy. I go to the gym each day and I'm in shape. No way any of those are torques below 300lbs.

I bought a 1/2" ratchet, 18" breaker bar, 14mmx1/2" socket, and two cans pf PB Blaster.....

Breaker bar wouldn't fix because I only had one single small jack and the car wasn't high enough but sure enough the PB came in handy. I got those nuts off with the quickness.

I must have been extremely lucky then - all I used on the bolts was about a 12" ratchet drive and one arm most of the time and I'm NOT a decent size guy. :icon17:

I'm gathering the tools now to do a hi-flo cat installation and believe me the bolts holding the cats in place are a PAIN!!!!

Glad to hear you got it going and hope the DIY was of some use. :tup:

I had to use my leg on a breaker bar to get those bolts off. The car was up on ramps, so I had to lie on my side, brace myself against the undercarriage, and push like hell with my foot. That was after soaking the bolts with PB Blaster, on a car that only had about 5k miles on it.

Shoot, my 12 year old did one side with a 1/4" ratchet and I did the other with the 3/8"....

and she had no problems! :roflpuke2::stirthepot:

Well I guess she's better than me!
:icon17:
Or, an 11 year old tightened your bolts at the factory, whereas a transformer-terminator-hulk hogan style robot did mine :rolleyes:

Truly amazes me that we are seeing this much variance in exhaust bolts when the Service Manual clearly states they aren't supposed to be that tight. I would still have a large box sitting in my garage if these bolts were anything like the catalytic converter bolts.

Guys... have a question on this DIY.

1) The black rubber brackets that support the muffler and mid sections have to be slid off the existing muffler hangars, correct? Hence the reason for some "lube".... so they have to be reused for any new muffler to be installed?

2) So does that mean the hangars on ANY aftermarket muffler (I ordered Invidia Gemini) must be located in the same relative location as the existing muffler so as to use the existing mounting holes on the car frame?

3) This was stated in Step 7: Step 7
The Y-Pipe has no such supports so simply remove the 4 bolts loosened before in Step 2 and it should come right off like this

Then what are the 2 black plastic looking pieces on either side of the Y pipe? Are those O2 sensors? Nothing was stated in the DIY for removing anything other than the bolts holding the Y pipe to the cat...

please clarify the above 3 points... thanks!

The hangers you remove will go right back on with any aftermarket exhaust built for the 370.
The rubber you see on the Y pipe are harmonic balancers. You don't need them on the aftermarket exhaust.

I love this forum... Thank you for the quick response. Makes a lot of sense now.

Thanks for clearing that up wheee! - I'm overseas in Mumbai, India on business this week - haven't seen a single 370Z but the Audi and Porshe dealerships have some sweet rides as does the Seven Islands Harley Davidson dealer. :)

Bring me back a Harley VRod if you're feeling generous....

the old stock bolts can be reused for the new system right?