My SS is all of a sudden sluggish... Help??! - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Melba Toast · 04-24-2014, 09:07 AM

Ok so I'm not quite sure what's the issue lately, but I did recently put on a SW retro chambered catback. With the stock exhaust it did still feel sluggish jumping off the line but did have a smooth acceleration up through.
Now since I got the exhaust though the car certainly sounds way better now, she feels super sluggish and when I hit 3K-4K the car chokes sounding like its gonna f'n blow up! Wtf is that?! Hard to describe the sound but like its struggling and pushing HARD high pitched whine ! I mean when it first happened as I was speeding up getting on the freeway ramp it scared me, though my engine was gonna blow! Or the tranny went.. Like it got stuck in N somehow! Really weird.
Did not have this symptom when I was bone stock. Admittedly she was still sluggish, even though I've put 91 in her since my ownership.

Took it to chevy since I have drivetrain warranty had they looked at it and said tranny and everything is fine. They are blaming the after market exhaust for what might be causing it.. One tech said it MAY be loss in back pressure.

I dunno.. Anyone else have this issue or something similar with their L99?!

2010SLVRBULIT · 04-24-2014, 09:14 AM

put original exhaust and see if problem follows. Can't fathom the new exhaust as the culprit though. Maybe bad fuel, MAF issues, no codes thrown? Heard that the AFM on those are a PITA.

nyrfan · 04-24-2014, 09:14 AM

There is not such thing as "loss in back pressure" on these cars, your dealer is an idiot.

Even though you have been running 91 octane, have you done a fuse pull? Also are you running an aftermarket CAI or any other mods? Any CEL?

Are you driving in "S" and maybe accidentally hitting the paddles?

BooSSted · 04-24-2014, 09:44 AM

No CEL? Disconnect your battery for a bit and try again.

gajagfan · 04-24-2014, 09:56 AM

One, sometimes what feels slow may not actually be slower. I will not comment on the lack of back pressure argument being real or not, but I will let you know that I had a similar experience with our 93 Z/28. During the development of the nitrous system for the LT1 engine, we had some raw fuel / air mixture make its way to the catalytic converter causing a big explosion and eventually leading to the cat being clogged. Knowing I could only go to the well once on this, I pulled the cat out, knocked the guts out of it, and put it back on the car. I expected an improvement in power due to less restriction. When I drove the car, I experienced just the opposite. Since I had no previous dyno or 1/4 mile times to compare, I do not know if this hurt the performance overall. It may be that the exhaust now flowed much better at high RPM, but I will guarantee you that it felt much worse at mid range (as you are experiencing).
For what its worth, the correction for the N2O system not causing the catalytic converter explosion was to close the spark plug gap, or install a spark enhancement system like an MSD box. Once we figured that out, we took the system off, and went and got the cat replaced by GM under warranty. That was a great car and a great engine. All testing was done with 89K on the engine. Car ran 13.0 sec quarter mile times on the stock Goodyears not hitting the the button until 2nd gear because we could not get it to hook. Fun times and a great job!

caverman · 04-24-2014, 10:06 AM

I would do a fuse pull and make sure to use a premium gas vendor. Change who you're getting your gas from and see if that doesn't help.

You might also check to see which version of the MAF sensor you have. It's possible you have the weak version.

The cat-back you put on should have absolutely nothing to do with making the car sluggish.....just like on the flip side adding just a cat-back isn't going gain you anything (other than sound) either.

KaBoom1701 · 04-24-2014, 10:15 AM

Did you put the exhaust on or did you have a shop do it?

sakipat · 04-24-2014, 10:52 AM

Sounds familiar. Mine was caused by a cracked sparkplug.

MikeSVX · 04-24-2014, 10:52 AM

Quote:

Originally Posted by BooSSted

No CEL? Disconnect your battery for a bit and try again.

^^ This. Just like when you put cheap gas in the car. The ECU has to adjust to the change. Disconnecting the battery, will reset it and it will relearn. I think it's just playing it safe because of the extra are flow and either dumping too much fuel or pulling timing.

jravenfan · 04-24-2014, 06:20 PM

Quote:

Originally Posted by MikeSVX

^^ This. Just like when you put cheap gas in the car. The ECU has to adjust to the change. Disconnecting the battery, will reset it and it will relearn. I think it's just playing it safe because of the extra are flow and either dumping too much fuel or pulling timing.

Fuse pull will do the same thing.

jravenfan · 04-24-2014, 06:22 PM

Quote:

Originally Posted by sakipat

Sounds familiar. Mine was caused by a cracked sparkplug.

I can see getting a cracked plug from header install, but not a cat back.

SSMickey · 04-24-2014, 08:21 PM

Could be a restricted CAT.

Melba Toast · 04-24-2014, 08:48 PM

Quote:

Originally Posted by nyrfan

There is not such thing as "loss in back pressure" on these cars, your dealer is an idiot.

Even though you have been running 91 octane, have you done a fuse pull? Also are you running an aftermarket CAI or any other mods? Any CEL?

Are you driving in "S" and maybe accidentally hitting the paddles?

No, I have not done the fuse pull yet. No other mods presently besides the catback. No CEL.

no not driving in S and didnt have my hands near the paddles.

jshaf · 04-24-2014, 08:50 PM

when I put my SW retro chambered Cat back on it had a tendency to almost stall at start up but it went away pretty quick. no noticeable issues since

04-24-2014, 09:07 AM	#1
Melba Toast Drives: 2011 Camaro 2SS/RS Join Date: Mar 2014 Location: Southern California Posts: 52	My SS is all of a sudden sluggish... Help??! Ok so I'm not quite sure what's the issue lately, but I did recently put on a SW retro chambered catback. With the stock exhaust it did still feel sluggish jumping off the line but did have a smooth acceleration up through. Now since I got the exhaust though the car certainly sounds way better now, she feels super sluggish and when I hit 3K-4K the car chokes sounding like its gonna f'n blow up! Wtf is that?! Hard to describe the sound but like its struggling and pushing HARD high pitched whine ! I mean when it first happened as I was speeding up getting on the freeway ramp it scared me, though my engine was gonna blow! Or the tranny went.. Like it got stuck in N somehow! Really weird. Did not have this symptom when I was bone stock. Admittedly she was still sluggish, even though I've put 91 in her since my ownership. Took it to chevy since I have drivetrain warranty had they looked at it and said tranny and everything is fine. They are blaming the after market exhaust for what might be causing it.. One tech said it MAY be loss in back pressure. I dunno.. Anyone else have this issue or something similar with their L99?!

04-24-2014, 09:14 AM	#3
nyrfan Let's go Rangers! Drives: 13' AGM 2SS/RS L99 Join Date: Jun 2011 Location: Orlando, FL Posts: 10,742 View My Garage	There is not such thing as "loss in back pressure" on these cars, your dealer is an idiot. Even though you have been running 91 octane, have you done a fuse pull? Also are you running an aftermarket CAI or any other mods? Any CEL? Are you driving in "S" and maybe accidentally hitting the paddles? __________________ Soprano 4/1/00-6/14/11, Gone but NEVER forgotten! FSP tuned: 377/389

04-24-2014, 09:44 AM	#4
BooSSted Drives: 2017 Z06 / 2012 CTS Join Date: Jul 2013 Location: NY Posts: 731	No CEL? Disconnect your battery for a bit and try again. __________________ SOLD - Maggie Powered 2011 2SS Procharged Powered 2017 Z06

04-24-2014, 10:06 AM	#6
caverman Drives: '69 SS Convertible Join Date: May 2009 Location: DFW, TX Posts: 7,111	I would do a fuse pull and make sure to use a premium gas vendor. Change who you're getting your gas from and see if that doesn't help. You might also check to see which version of the MAF sensor you have. It's possible you have the weak version. The cat-back you put on should have absolutely nothing to do with making the car sluggish.....just like on the flip side adding just a cat-back isn't going gain you anything (other than sound) either. __________________ *-2010 Camaro* 2SS \| M6 \| VR w/White Stripes \| 1 3/4" KOOKS - 3" Magnaflow \| LPE 3.91 gears \| ADM tuned \| Halltech w/ADM Scoop \| Spohn/BMR Trailing Arm/Toe Rod \| BC Coilovers\| Pedders FE4 ZL1 swaybars \| Cradle/Diff/Radius Rod bushings \| VMax TB \| Morimoto Projectors \| MGW shifter \| Red Calipers Build Journal

04-24-2014, 10:15 AM	#7
KaBoom1701 KaBoom1701 Drives: 13' ZL1 Red M6 Join Date: Dec 2012 Location: I.E. SoCal (Yucaipa) Posts: 8,630	Did you put the exhaust on or did you have a shop do it? __________________ Mods: Roto-Fab Intake, WW Res. kit & Big Gulp Air Scoop, Elite Catch Can, ATI Super Damper & 18% OD Pulley, LF Idler pulley bracket, Metco CC breather, ID850 Injectors, Stainless Power Headers w/ ceramic coating, TR71X Spark Plugs, JMS Fuel Pump Booster, Bo White TB, Tuned by Ted @ Jannetty Racing, Ron Davis HX, D3 Reservoir, Pfadt 1" Springs, Moreno Camber Plates, ZL1 Addons Splitter guard washers, Tow Hook kit & rock guards, Hurst Shifter Billet Plus 6 Speed Short Shifter, ZL1 DRL lighting harness, ZL1 Recaro Seats.

04-24-2014, 09:14 AM	#2
2010SLVRBULIT Drives: G5(LLT) & C6(LS3) Join Date: Apr 2009 Location: MARS Posts: 7,527 View My Garage	put original exhaust and see if problem follows. Can't fathom the new exhaust as the culprit though. Maybe bad fuel, MAF issues, no codes thrown? Heard that the AFM on those are a PITA.

04-24-2014, 09:56 AM	#5
gajagfan Drives: 2013 1SS 1LE Black - Std Exhaust Join Date: Mar 2013 Location: Brunswick, GA Posts: 3,622 View My Garage	One, sometimes what feels slow may not actually be slower. I will not comment on the lack of back pressure argument being real or not, but I will let you know that I had a similar experience with our 93 Z/28. During the development of the nitrous system for the LT1 engine, we had some raw fuel / air mixture make its way to the catalytic converter causing a big explosion and eventually leading to the cat being clogged. Knowing I could only go to the well once on this, I pulled the cat out, knocked the guts out of it, and put it back on the car. I expected an improvement in power due to less restriction. When I drove the car, I experienced just the opposite. Since I had no previous dyno or 1/4 mile times to compare, I do not know if this hurt the performance overall. It may be that the exhaust now flowed much better at high RPM, but I will guarantee you that it felt much worse at mid range (as you are experiencing). For what its worth, the correction for the N2O system not causing the catalytic converter explosion was to close the spark plug gap, or install a spark enhancement system like an MSD box. Once we figured that out, we took the system off, and went and got the cat replaced by GM under warranty. That was a great car and a great engine. All testing was done with 89K on the engine. Car ran 13.0 sec quarter mile times on the stock Goodyears not hitting the the button until 2nd gear because we could not get it to hook. Fun times and a great job!

04-24-2014, 10:52 AM	#8
sakipat Drives: 2010 Camaro 2SS RS Join Date: Dec 2012 Location: San Diego Posts: 97	Sounds familiar. Mine was caused by a cracked sparkplug.

04-24-2014, 08:21 PM	#12
SSMickey Drives: 2010 IBM 2SS Join Date: Feb 2010 Location: Columbia S.C. Posts: 1,455 View My Garage	Could be a restricted CAT. __________________ ProCharger P1X, Vengeance Racing Kaotic Cam, ARH Headers and Exhaust with Borla ATAK mufflers, MGW Shifter, MTI Drop Springs, Forgeline RB3C Wheels, 3.91 gears, Night Owl LED Control System

04-24-2014, 08:50 PM	#14
jshaf Montani Semper Liberi Drives: 2011 Black 2SS/RS w/ IOM stripes Join Date: Feb 2010 Location: Masontown, WV Posts: 4,841	when I put my SW retro chambered Cat back on it had a tendency to almost stall at start up but it went away pretty quick. no noticeable issues since __________________ Stainless Works 1 7/8 Long Tude Headers, Stainless Works High Flow Cats, Stainless Works Retro Chambered Catback, Z/28 Air Intake, RDP Tuned, FR41 Chrome Rims, 1100W stereo, 35% Tint