Screeching exhaust noise after 2nd cat delete

2017 Black-Red 2SS · 03-17-2017, 12:34 PM

Hoping someone could help me out here:

I did a 2nd cat delete and a little while after, my exhaust began making a screeching sound, on the right side.

It seems to be the valve, from the NPP exhaust, more lose than the left, . It only happens when I accelerate lightly, but its a very loud and annoying sound. The exhaust shop said there is nothing we can do with it. Any idea?

Hoping someone has seen this happen and fixed it without doing a whole new cat-back for 1500...

Megahurtz · 03-17-2017, 02:39 PM

Do you have AFM? How did you delete the secondary cats?

SuperSound · 03-17-2017, 03:02 PM

See if you can get a video of it. Also to check if it's NPP valve...put it manually in stealth setting and see if it stops.

SanDMaN2091 · 03-19-2017, 12:17 PM

ive had the same problem with the passenger side valve right behind tips... spayed some lube in small hole of npp valve while using pair of pliers to manually open the valve, done it twice in 2 weeks but hasnt made a peep in over a month..

03-17-2017, 12:34 PM	#1
2017 Black-Red 2SS Drives: 2017 Black-Red 2SS Join Date: Jan 2017 Location: Miami Posts: 5 View My Garage	Screeching exhaust noise after 2nd cat delete Hoping someone could help me out here: I did a 2nd cat delete and a little while after, my exhaust began making a screeching sound, on the right side. It seems to be the valve, from the NPP exhaust, more lose than the left, . It only happens when I accelerate lightly, but its a very loud and annoying sound. The exhaust shop said there is nothing we can do with it. Any idea? Hoping someone has seen this happen and fixed it without doing a whole new cat-back for 1500...

03-17-2017, 03:02 PM	#3
SuperSound Drives: '17 Camaro 2SS A8 Join Date: Jan 2015 Location: Eastern NC Posts: 5,063 View My Garage	See if you can get a video of it. Also to check if it's NPP valve...put it manually in stealth setting and see if it stops. __________________ Current: '17 2SS Hyper Blue, A8, MRC, NPP Past: '99 SS Camaro A4, '73 Camaro 383 A3 "Voices in your head are not considered insider information." 3800 Status - 6/16/16 (Built!) 6000 status - 6/29/16 (Delivered!)

03-19-2017, 12:17 PM	#4
SanDMaN2091 Drives: 2016 Camaro SS A8 NPP Join Date: Nov 2016 Location: Dallas, Tx Posts: 145 View My Garage	ive had the same problem with the passenger side valve right behind tips... spayed some lube in small hole of npp valve while using pair of pliers to manually open the valve, done it twice in 2 weeks but hasnt made a peep in over a month.. __________________ DMS Flex Fuel-E85 HPTuners Ngauge Roto Fab CAI, *LPE* Ported/Polished 95mm LT5Throttle Body, *PRAY* Ported MSD Intake Manifold, SP Coated TSP 1 7/8" Catlless Longtubes Hooker BlackHeart Cat-Back, Mishimoto Catch Can (Which always has some nasty in it) *Instagram@Weapon_6*

03-17-2017, 02:39 PM	#2
Megahurtz Snackbar Tuning Drives: 2023 SGM ZL1 Join Date: Oct 2016 Location: Florida Posts: 1,513	Do you have AFM? How did you delete the secondary cats?

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