[somewhatdamaged]

Alright fellas,
Here’s my rank novice’s review and install notes for the ZZP downpipe with high flow cat. I wanted to post my observations, and issues that some of you weekend modders may encounter. I love tinkering with my cars, and can handle the most basic of maintenance like oil changes and easy-peasy mods like a cold air intake and minor cosmetic mods. Anything beyond that, it’s all research, and learn as I go. What would take more experienced/skilled dudes a couple of hours will take me 5 or 6 hours. Anyhow, I love the learning, and challenge of it all, and find it fun and rewarding. Check out the pix below!

To start, the 4 top bolts are really on there tight from the factory. PB Blaster worked great, along with a swivel type extension to reach the bottom two bolts. I also loosened the side heat shield which allowed a little more room for my ratchet head and allowed me to the proper angle to break them loose. Also, it helped for tightening and torqueing the new bolts on the ZZP piece. ZZP does provide new gaskets for both ends. I used the torque specs I found here: http://www.pfadtracing.com/pdfs/cadi...stallation.pdf This install guide had the most detailed instructions of any guide I could find online from the various companies.

As I mentioned in my other post, I ran into problems with the downstream O2 sensor connector. Thanks to cooper1965 who provided pics and advice, I figured it out. I’m sure many of you will not have the issue I had, but for whatever reason, it stumped me for a bit. I ended up reaching it easier from the top, allowing me to use both hands to grip and pull the connector apart.

The other area I had issues with was the downstream O2 sensor rubbing the transmission cooler line. I read all the posts on Camaro6 related to this. I ended up calling ZZP. While they don’t have someone answering tech calls live, they do specify on their message that someone will call you back. Sure enough, I got a call a couple of hours later. While some part manufactures make good product, you don’t always get good customer service. ZZP came through big time for me. I fail to remember the tech guy’s name, but he talked me through the process. He mentioned as others have that it’s a common issue on some Camaros and the ATS, but that bending the line wasn’t that big of a deal. I felt confident after our conversation, thanks ZZP! He was right, it’s really not a big deal. I applied even pressure, used a small pry bar and didn’t yank on it. Just even pressure and sure enough it starts to move and you get your clearance. While doing this I had the bolts just hand tight on the top, bottom, and the bracket. Speaking of the bracket, it does line up properly. I found that if you connect the bracket before you tighten the top 4 and bottom 2 bolts it lines up fine. I torqued the top four bolts first, I then rechecked my clearance of the O2 sensor again. I again applied even pressure and gave a little more clearance. I then torqued the bracket, and finally the rear two bolts.

As far as the ZZP downpipe, it’s a high quality piece for a great price, and great welds! It’s much lighter than the stock piece. It gives a decent growl to the stock exhaust, more from the outside as the cabin remains pretty quiet. You do hear it more when you get on it. Mid range and upper RPM’s you can feel a decent increase in torque. There is NO CEL. I’ve driven the car over 100 miles now. and no leaks so far. I've rechecked the bolts, all is good and solid! Obviously, a good tune would really allow it to shine. Since it’s my wife’s daily driver, this is a low cost way to get a bit more sound/performance, and a nice intro piece to some other mods.

At some point, when I get frustrated, stuck, and really tired it’s easy to want to just give up and call in the professionals. When I’m able to finish a project, and install it right, I feel a sense of accomplishment -much better than having someone do it for you. I view the forums as a place to learn, as well as discuss our favorite Chevy car. It’s great that we have forum members that are willing to help out the unskilled modder like myself. Thanks all.
Somewhatdamaged

Here's the bane of my existence - conquered!
Stock pipe is out!
ZZP versus stock
High flow Cat 400 Cell
O2 sensor removed! PB Blaster/O2 socket are your friends!


Downstream O2 installed and torqued!

[Start The Machine]

Great write up. I appreciate all of your insight on this. Going to be doing mine soon.

[Jason@JacFab]

Nice write up.

I may add for anyone that reads this before doing an install... I completely removed the heat shield on the turbo. This allowed me access to all 4 nuts that hold the DP to the turbo, as well as the upper DP mounting bracket from the top top of the car. Eliminated the need for long extensions and swivel heads on the ratchet. The only thing I couldn't do from the top were the lower mounting bracket and 2 nuts that bolt the bottom of the DP to the catback.

Not sure if this saved me time, but it sure felt like an easy install. Took me bout 45min.

[somewhatdamaged]

Thanks! Damn, wish I had thought of removing that whole thing. Getting the car jacked up and getting my tools ready took about 45 minutes for me LOL I used to have a local guy who did a lot of my mods on my 2010 SS. He had his own shop, and was totally cool with me hanging out in the shop, talkin' cars and watching him work. I always marvel at how a skilled mechanic can make stuff look so easy and complete the work quick and proper.

[Michigan1LTRS]

Awesome stuff!! Thank you for this.

[ChicagoTommy]

Awesome write up! I told you anyone could accomplish this! Hopefully more people will feel comfortable with getting their hands dirty. This isn't much more difficult than installing a CAI. Glad you like it, but now you need to get a tune to take advantage of the extra power!

[somewhatdamaged]

Originally Posted by ChicagoTommy

Awesome write up! I told you anyone could accomplish this! Hopefully more people will feel comfortable with getting their hands dirty. This isn't much more difficult than installing a CAI. Glad you like it, but now you need to get a tune to take advantage of the extra power!

Thanks Chicago,
Yeah, I almost gave up there for awhile LOL. I really want to get a tune, but want to keep my warranty, especially since it's my wife's. I may just have to go full on mod crazy on my 2SS to satisfy my mod cravings.

[somewhatdamaged]

Quick update:
Now with over 200 miles, everything is solid. Did a close to WOT run "for testing purposes only" on patch of open, uncrowded highway - damn it pulls hard! Wife loves the extra sound, maybe time to jump on a Borla S-Type? LOL

For those doing this mod, hit me up with any questions, be happy to help! Thanks all

[Start The Machine]

Originally Posted by somewhatdamaged

Quick update:
Now with over 200 miles, everything is solid. Did a close to WOT run "for testing purposes only" on patch of open, uncrowded highway - damn it pulls hard! Wife loves the extra sound, maybe time to jump on a Borla S-Type? LOL

For those doing this mod, hit me up with any questions, be happy to help! Thanks all

Ordered mine yesterday. Cant wait to install it. Post a sound clip if you can.

[somewhatdamaged]

Originally Posted by Start The Machine

Ordered mine yesterday. Cant wait to install it. Post a sound clip if you can.

Will do!

[ChicagoTommy]

Originally Posted by somewhatdamaged

Quick update:
Now with over 200 miles, everything is solid. Did a close to WOT run "for testing purposes only" on patch of open, uncrowded highway - damn it pulls hard! Wife loves the extra sound, maybe time to jump on a Borla S-Type? LOL

For those doing this mod, hit me up with any questions, be happy to help! Thanks all

That's gonna be LOUD. Personally I detest loud.

[somewhatdamaged]

Originally Posted by ChicagoTommy

That's gonna be LOUD. Personally I detest loud.

While the high flow downpipe added a little more exhaust noise, it's still pretty quiet inside. I have the Borla ATAK on my 2SS, with a secondary cat delete and it's still not too loud and no drone when cruising. I'm really sensitive to drone and it seems my wife is not, she really doesn't hear any added volume in the 2.0 so I think the Borla S-Type will be good. Bad news is, it's too damn expensive for two mufflers LOL. I'll probably wait awhile on an any exhaust unless I find a good deal on a used one. The only cheap option would be a muffler delete, and that I feel would be too loud.

[AdamJT11]

Good stuff, thanks for sharing.
So you guys all think its fine to run a catted downpipe without a tune? I'm thinking about doing the same thing but wasn't sure if I should hold off until Im getting tuned.

[Evil-Bee-NH]

Originally Posted by AdamJT11

Good stuff, thanks for sharing.
So you guys all think its fine to run a catted downpipe without a tune? I'm thinking about doing the same thing but wasn't sure if I should hold off until Im getting tuned.

Running the Catted Downpipe without a tune won't hurt anything. Catless you run the risk of causing issues.

You'll see the same experience most ZL1 owners got when they put long tubes on their cars with a previous tune. Your not going to smash higher numbers with the tune but cause everything to run better with a tune. Biggest jump you'll see is with the Downpipe Catted or Catless and a CAI. Better breathing turbo makes better power reasoning.