[chrest]

Originally Posted by Tr6

After a change it takes the ECU 150ish miles to get all the parameters corrected, so it should disappear since you fixed it.

right on. thanks for the info.

[Tr6]

Originally Posted by chrest

right on. thanks for the info.

NP! Let us know if/when it disappears!

[chrest]

Originally Posted by Tr6

NP! Let us know if/when it disappears!

will do. I wasn't too worried about it since i did find the obvious issue so it should hopefully go away.

[Tr6]

Originally Posted by chrest

will do. I wasn't too worried about it since i did find the obvious issue so it should hopefully go away.

Yeah, damn sensitive sensors lol. I actually had a p420 after slapping on the AFE intake (dry filter) and driving for about 50 miles... I didn't care enough to keep the CEL for 100 miles more so I just went back to stock intake with K&N drop in (not for power, just so the car breathes a bit better than the stock klenex filter). No one likes a CEL!

[MAGAUSA]

Originally Posted by CreativeDawn

When I got my cat delete, I did 2.5 inch piping (smaller then factory piping. I'm going to have it re-done to 3.00 piping in about a week by just increasing the diameter size a slight bit. I'm sure the sound difference will be slight for the better even though my car is loud as hell even without my cutouts open lol.

Likely won't make a difference though. The sound changed dramatically for me with the Borla mid pipe. Don't know how much if any is related to the downstream change (x pipe vs stock x pipe). Best exhaust I could have wanted with NPP for the price.

[ninetres]

Originally Posted by Tr6

A couple things people seem to miss is... especially with aftermarket catbacks. You absolutely HAVE TO CUT the pipe right before the muffler or flatout cut the cats out.

Stock exhaust = shorty triy headers, primary cats and xpipe WITH axleback. There are only 3 parts to it thus if you take out the secondary cats you don't have a single option but to cut the stock catback at some point. Unless you absolutely get an axle back with xpipe (full catback) combo but not if you wanna keep the stock axleback.

Given you leave stock headers and primary cats alone... In order to replace the secondary cats, you have to either just "surgically" remove them or when you get an xpipe (like me, I have borla catless), you remove the front part that just bolts on to the back of the primary cats and then CUT before the muffles for welding/clamp.

Another thing. SS stock exhaust (also C7s) are 2.75' and you really want to keep the parts you replace that size. LT1 is absolutely perfect with 2.75' exhaust. Going 2.5 or 3 actually hurts and doesn't benefit anything (feel free to look for Borla's research on this as well as talk to Chevy engineers if you see them at an event) where as LT4 (ZL1 and Zo6 AND Ctsv) has 3's all around because that's what the engine works best with.

Also, when replacing secondary cats... Especially on manual, as long as you don't have any leaks due to install (make sure the welder uses an arcing welder and not straight one because he won't be able to weld the top of the pipe thus causing a leak and that leads to CEL) you won't have any issues. I've had mine installed almost a year ago now and zero CELs. As for the A8, you may have to reset the AFM parameters by disconnecting the battery and all. Not sure how it works as I have an m6 but feel free to contact the exhaust manufacturer and they will guide you on how to.

I did my best to get a string around my ZL1 exhaust in a couple spots and it seems closer to 2.75" to me. You sure OEM ZL1 stock exhaust is 3"? I spoke to Corsa on the phone today too and he explained why their system is 2.75" as well. Are you saying Corsa is DOWNSIZING the ZL1 exhaust?

Sorry. Confused new owner.

[Tr6]

Originally Posted by ninetres

I did my best to get a string around my ZL1 exhaust in a couple spots and it seems closer to 2.75" to me. You sure OEM ZL1 stock exhaust is 3"? I spoke to Corsa on the phone today too and he explained why their system is 2.75" as well. Are you saying Corsa is DOWNSIZING the ZL1 exhaust?

Sorry. Confused new owner.

Thank you for posting, I was TOTALLY wrong. I did some digging around on this (my initial knowledge was gained up in MI during 50th Camaro and was wrong) so I apologize for BS info.

ZL1 exhaust is indeed 2.75. So is the C7 Zo6.

The C7 Zo6 guys have found that they lose power and their powerband is weaker when they add 3'' corsa catback with NO cats on their cars, Not by much... like a couple HP which you can just say it wasn't the catback but maybe the element change (car heating up more after a couple pulls, wind shifted etc).

It makes complete sense that Corsa has released 2.75s for the ZL1, good for them!

[SSTony]

I was looking at that kit and only the passenger side secondary cat is bolted. drivers side secondary is welded in. you will have to cut that right?

Originally Posted by Tr6

Bolts right onto the primary cats and then you cut before the muffler (exact measurement is in the install guide, cannot remember of the top of my head).

[JeromeS13]

Originally Posted by SSTony

I was looking at that kit and only the passenger side secondary cat is bolted. drivers side secondary is welded in. you will have to cut that right?

Both secondary cats are bolted. Passenger side uses a traditional exhaust flange, while the driver side uses a circular clamp.

[SSTony]

yea I just noticed that. with the 60626 you can do it clean but you will still have to cut somewhere unless you use the 60606 system and it should take you all the way back to the muffler. then all you do is cut and clamp or weld it.

[ninetres]

Originally Posted by SSTony

yea I just noticed that. with the 60626 you can do it clean but you will still have to cut somewhere unless you use the 60606 system and it should take you all the way back to the muffler. then all you do is cut and clamp or weld it.

Or take the OEM catback off in one piece, and hook the borla mod section up to an axle back. Or have your own built.

I just ordered a Corsa extreme axle back, and will be having a custom 2.75" stainless mid section built that removes 2nd cats. Can't wait.

[SSTony]

You can remove the secondary cat back without cutting with the borla but at some point if you keep the stock muffler you will have to cut it and mount it. I have the NPP and love the sound and want to keep the GM muffler

[ninetres]

Originally Posted by SSTony

You can remove the secondary cat back without cutting with the borla but at some point if you keep the stock muffler you will have to cut it and mount it. I have the NPP and love the sound and want to keep the GM muffler

True, then you have to cut it. I'm weird and don't want to hack up the OEM exhaust. Going to hang it from my garage ceiling

[CruzySS]

Any pics of the Borla PN 60606 after install?