Does Secondary Cat Delete Increase Pops? Cause CEL? - Page 3

keon718nyc · 05-22-2017, 08:46 PM

Quote:

Originally Posted by MAGAUSA

Stock width is 2.75? You used 3 and sleeved it over the stock?

Correct, The muffler place only had 3" and crimped the ends pretty much.

MAGAUSA · 05-22-2017, 09:05 PM

Quote:

Originally Posted by keon718nyc

Correct, The muffler place only had 3" and crimped the ends pretty much.

So basically they weld the living hell out of the connections and all is good? I am considering the Borla mid pipe to essentially "clean up" the mid section and get rid of the second cat, but that's a lot of money for that and I don't know if it will mate up to a kooks high flow cat when I eventually do headers. I'd rather get a good weld job and cut out these cans for now.

The stock npp is essentially a straight pipe with perforations in the pipe, which does reduce some sound. But still, what the hell would I gain from an aftermarket muffler unless I just wanted extremely loud? All this Borla crap with them redesigning their valves and not able to provide a finished product makes me feel like an idiot for paying what they charge to change the mufflers when compared to the stock npp. One of the reasons was to get rid of the rattling valves, but then Borla has the same friggin problem! At least I have the Chevy warranty and since it's exhaust, they will fix it if the problem comes back. I'm rambling.

I want to do what youv'e done. Tomorrow. Can't because of work, but want to.

AxiomVerge · 05-23-2017, 01:26 AM

Quote:

Originally Posted by TJay74

Depends on if your state follows the California C.A.R.B. smog program or not.

Well I might be moving to CA so I guess that about settles it...

Sent from my SM-G935T using Tapatalk

keon718nyc · 05-23-2017, 09:44 AM

Quote:

Originally Posted by MAGAUSA

So basically they weld the living hell out of the connections and all is good? I am considering the Borla mid pipe to essentially "clean up" the mid section and get rid of the second cat, but that's a lot of money for that and I don't know if it will mate up to a kooks high flow cat when I eventually do headers. I'd rather get a good weld job and cut out these cans for now.

The stock npp is essentially a straight pipe with perforations in the pipe, which does reduce some sound. But still, what the hell would I gain from an aftermarket muffler unless I just wanted extremely loud? All this Borla crap with them redesigning their valves and not able to provide a finished product makes me feel like an idiot for paying what they charge to change the mufflers when compared to the stock npp. One of the reasons was to get rid of the rattling valves, but then Borla has the same friggin problem! At least I have the Chevy warranty and since it's exhaust, they will fix it if the problem comes back. I'm rambling.

I want to do what youv'e done. Tomorrow. Can't because of work, but want to.

Yes, any decent welder can do this in 30-40 minutes total. The gains on aftermarket systems won't be really noticeable i presume unless other mods are present and if you are just looking for a better raspier/deeper sound then i would just do the 2nd Cat deletes. If you already paid for NPP why remove it is my thinking.

MAGAUSA · 05-23-2017, 10:22 AM

Quote:

Originally Posted by keon718nyc

Yes, any decent welder can do this in 30-40 minutes total. The gains on aftermarket systems won't be really noticeable i presume unless other mods are present and if you are just looking for a better raspier/deeper sound then i would just do the 2nd Cat deletes. If you already paid for NPP why remove it is my thinking.

That's what I'm thinking now.

obarry13 · 05-23-2017, 02:08 PM

I've been going back and forth on doing this for a couple of weeks now, but it sounds like people really are enjoying the sound and there is very little drone as well. I was quoted $200 to do this right around the corner from my work, so that sounds reasonable.

mjk3888 · 05-23-2017, 03:18 PM

Quote:

Originally Posted by obarry13

I've been going back and forth on doing this for a couple of weeks now, but it sounds like people really are enjoying the sound and there is very little drone as well. I was quoted $200 to do this right around the corner from my work, so that sounds reasonable.

Since its illegal they kinda name their price, but I got mine done for $20 a weld, so $80 total.

mjk3888 · 02-07-2018, 03:18 PM

Got a p0420 code for Cats today. I think my stupid dealer already sent a request to GM for a new primary cat. I hope they don't void my damn warranty. Anyone else get the P0420 code after, several months with deleted secondary cats and no CELs?

Ventmaster · 02-07-2018, 09:33 PM

I finally went with Borla's 60606 2nd cat delete X-pipe/mid-pipe to do away with cutting ( although I'll cut at the NPP intersection) and do away with the factory resonators ...

And get rid rid of the many factory pipe impediments. I had already cut out the rear smashed pipe and should be able to bolt the 60606 without much more drama. And as always- should be able to bolt the stock system back in without too much effort either.

I like the stock NPP sound (but want a little more) and I just don't trust any local exhaust shop to not mess up the welds and/or O2 sensors in the transfer. As the old saying goes "you get what you pay for".

I'm still pissed off at Borla for making us pay this much... but hoping its worth it in the long run!

If you are just paying a shop to cut out the 2nd cats you are keeping these factory restrictions.

SloCal · 03-08-2018, 01:12 PM

Quote:

Originally Posted by mjk3888

Got a p0420 code for Cats today. I think my stupid dealer already sent a request to GM for a new primary cat. I hope they don't void my damn warranty. Anyone else get the P0420 code after, several months with deleted secondary cats and no CELs?

Any update on this? Want to get this done on Saturday but don't want to deal with CEL and the o2 sensor. shops won't confirm if they have flex mig welders.

mjk3888 · 03-08-2018, 01:54 PM

Quote:

Originally Posted by SloCal

Any update on this? Want to get this done on Saturday but don't want to deal with CEL and the o2 sensor. shops won't confirm if they have flex mig welders.

They claimed it was in fact a bad cat and replaced the primary cat under warranty. Code has yet to return.

SloCal · 03-09-2018, 04:27 PM

Quote:

Originally Posted by mjk3888

They claimed it was in fact a bad cat and replaced the primary cat under warranty. Code has yet to return.

Thanks for letting me know. gonna pull the trigger

JK001 · 03-11-2018, 07:07 PM

Quote:

Originally Posted by mjk3888

They claimed it was in fact a bad cat and replaced the primary cat under warranty. Code has yet to return.

So did they question you why you don't have your secondary cats? I can imagine a dealer saying you modded, you broke it- no warranty l

FrostySS · 03-14-2018, 10:50 PM

Quote:

Originally Posted by JK001

I can imagine a dealer saying you modded, you broke it- no warranty l

The primary cats and secondary cats are completely separate and irrelevant to each other.

View Poll Results: Did you get a Check Engine Light after removing Secondary Cats?
Yes	5	7.25%
No	64	92.75%
Voters: 69. You may not vote on this poll

02-07-2018, 03:18 PM	#36
mjk3888 "M1SS1LE" Drives: 2017 SS 1LE Join Date: Dec 2015 Location: Upstate SC Posts: 2,906	Got a p0420 code for Cats today. I think my stupid dealer already sent a request to GM for a new primary cat. I hope they don't void my damn warranty. Anyone else get the P0420 code after, several months with deleted secondary cats and no CELs? __________________ MJK3888 Instagram Link

02-07-2018, 09:33 PM	#37
Ventmaster Drives: 2017 1SS 6spd Join Date: Jan 2011 Location: Utah Posts: 2,869	I finally went with Borla's 60606 2nd cat delete X-pipe/mid-pipe to do away with cutting ( although I'll cut at the NPP intersection) and do away with the factory resonators ... And get rid rid of the many factory pipe impediments. I had already cut out the rear smashed pipe and should be able to bolt the 60606 without much more drama. And as always- should be able to bolt the stock system back in without too much effort either. I like the stock NPP sound (but want a little more) and I just don't trust any local exhaust shop to not mess up the welds and/or O2 sensors in the transfer. As the old saying goes "you get what you pay for". I'm still pissed off at Borla for making us pay this much... but hoping its worth it in the long run! If you are just paying a shop to cut out the 2nd cats you are keeping these factory restrictions. Attached Images Last edited by Ventmaster; 02-07-2018 at 09:54 PM.

05-23-2017, 02:08 PM	#34
obarry13 Drives: 2016 Camaro 2SS Join Date: Dec 2015 Location: Tampa, FL Posts: 243	I've been going back and forth on doing this for a couple of weeks now, but it sounds like people really are enjoying the sound and there is very little drone as well. I was quoted $200 to do this right around the corner from my work, so that sounds reasonable.

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