Strange problem with L99 - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

EJSS · 02-23-2021, 10:32 PM

I'm having a strange issue with my car, 2010 Camaro SS with L99. I first noticed it the other day when I got on the highway and tried to open it up a little, the car felt really slow, it got up to about 85 MPH and then it just rev'd high and wouldn't continue to accelerate. I then noticed a burning smell coming from my vents. I then panicked and wrecked my car into a tree.

Then I died.

But then I arose from the dead and realized that the tree part never actually happened, so I continued to drive (slowly this time) and I noticed the exhaust rumble seemed different, almost like a cylinder or 2 was misfiring. The car felt (and still feels) like it's in limp mode, yet I have NO CEL and NO MESSAGES on the display. The car had been running perfectly for over a year, this just suddenly happened and continues to happen everytime I start the car. I feels and sounds like it's idling normal for the most part...

The car is totally stock with the exception of 2 things: I have JBA highflow cats with the rear o2 extenders, and I have a GM performance (Z/28) cold air intake. No tune. The fuel trims have always been single digits so I didnt think a tune was necessary.

I plugged in the OBD2 scanner tool and opened up the car scanner pro app to see what was going on. The 1st screenshots below shows the diagnostic tests that run automatically, and the other screenshot is the live-data/all-sensors-screen while the car was at idle.

Not sure why the o2 sensor test and the o2 sensor heating test come back as failed... When i check the values on the live data screen, they seem to be working fine...

You guys are a lot smarter than me, any ideas? Thanks in advance.

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102SS · 02-24-2021, 06:17 AM

Has it been parked for a while?

Is your gas fresh?

Did you do the 5/20 fuse pull to reset it?

EJSS · 02-24-2021, 05:33 PM

Quote:

Originally Posted by 102SS

Has it been parked for a while?

Is your gas fresh?

Did you do the 5/20 fuse pull to reset it?

I drive it everyday

Yes, gas is only a few days old.

Yes, I did the fuse(s) pull 3 times.

Also, I need to edit my post, i realize now that those tests in the first screenshot didnt actually fail, I just didnt complete a full "drive cycle" so the tests never got completed. The software says fail when actually they never ran.

MericanMuscle · 02-24-2021, 05:36 PM

Wonder if your fuel pump is crapping out?

EJSS · 02-24-2021, 09:16 PM

Quote:

Originally Posted by MericanMuscle

Wonder if your fuel pump is crapping out?

Just changed the fuel pump about a year and a half ago, and boy was that an annoying job... had to take half the damn car apart just to get to it.

EJSS · 02-24-2021, 09:21 PM

Update: Ran the car through an entire "drive cycle" and all tests came back as "passed" except for o2 sensors and catalyst. O2 sensors / fuel trims seem to be fine on live data.

On my way to the gym just now, I had my windows down and heard what sounded like bees in a tin can directly under me. My first thought is probably these cheap ass JBA cats.. kind of strange that they'd have such a huge impact on the performance though.. I guess some of the honeycomb material broke loose and is blocking flow? Figures I hear bees in my honeycomb... anyway, I'm going to take the cats off and inspect and I'll report back.

EJSS · 02-25-2021, 12:00 AM

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morepowerjoe · 02-25-2021, 12:56 AM

That looks horrible.

Ashen 6.2 · 02-25-2021, 05:25 AM

Quote:

Originally Posted by EJSS

Attachment 1059850

Yikes! Time to replace those cats..

hunter1660 · 02-25-2021, 06:12 AM

Wow...

TheFlyingBananaSS · 02-25-2021, 06:24 AM

Wow. Just WOW.

Aqua Blue RS/SS · 02-25-2021, 07:14 AM

Yep that’ll do it.

102SS · 02-25-2021, 07:34 AM

Glad you got it figured out.

1JEWLDSSRS · 02-25-2021, 07:59 AM

Wow!! Never seen cats look like that before!! Glad you figured that out. Wow...

02-23-2021, 10:32 PM	#1
EJSS Drives: 2010 Camaro SS L99 Join Date: May 2019 Location: New Orleans Posts: 119	Strange problem with L99 I'm having a strange issue with my car, 2010 Camaro SS with L99. I first noticed it the other day when I got on the highway and tried to open it up a little, the car felt really slow, it got up to about 85 MPH and then it just rev'd high and wouldn't continue to accelerate. I then noticed a burning smell coming from my vents. I then panicked and wrecked my car into a tree. Then I died. But then I arose from the dead and realized that the tree part never actually happened, so I continued to drive (slowly this time) and I noticed the exhaust rumble seemed different, almost like a cylinder or 2 was misfiring. The car felt (and still feels) like it's in limp mode, yet I have NO CEL and NO MESSAGES on the display. The car had been running perfectly for over a year, this just suddenly happened and continues to happen everytime I start the car. I feels and sounds like it's idling normal for the most part... The car is totally stock with the exception of 2 things: I have JBA highflow cats with the rear o2 extenders, and I have a GM performance (Z/28) cold air intake. No tune. The fuel trims have always been single digits so I didnt think a tune was necessary. I plugged in the OBD2 scanner tool and opened up the car scanner pro app to see what was going on. The 1st screenshots below shows the diagnostic tests that run automatically, and the other screenshot is the live-data/all-sensors-screen while the car was at idle. Not sure why the o2 sensor test and the o2 sensor heating test come back as failed... When i check the values on the live data screen, they seem to be working fine... You guys are a lot smarter than me, any ideas? Thanks in advance.

02-24-2021, 06:17 AM	#2
102SS waiting at the tree Drives: SIM 2010 2SS/RS A6 Join Date: Apr 2013 Location: Niagara Falls Posts: 3,144	Has it been parked for a while? Is your gas fresh? Did you do the 5/20 fuse pull to reset it? __________________ 2010 2SS/RS A6 ZL1 Rims 60ft 2.03 13.08 at 107.82 (4/28) 2009 Pontiac G8 3.6L the DD

02-25-2021, 12:56 AM	#8
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,105	That looks horrible. __________________ DSS FX Forged Pistons, Eagle ESP L19 Forged Rods, ARP Head and Main Studs, TSP PRC 260 CNC Ported Heads milled .030, Cometic .040 Head Gaskets, GPI SS3 VVT Camshaft, GM Performance Racing Lifters, CHE Trunnions , Molly Pushrods, Melling 10355HV Oil Pump, Cold Air Inductions CAI, Fast LSXR Intake Manifold, Nick Williams 103 TB, TSP 1 7/8" Longtubes with 3" TSP Exhaust, ZL1 Fuel Pump, Mishimoto Radiator, Mishimoto Oil Cooler, Tru Cool 40k Tranny Cooler, 3600 Circle D Converter, Fluid Dynamics Balancer Build Thread https://www.camaro5.com/forums/showthread.php?t=609817

02-25-2021, 06:12 AM	#10
hunter1660 Drives: 2011ss/rs camaro Join Date: Sep 2011 Location: florida Posts: 1,261	Wow... __________________ . OBX LTH,Rotofab,Magnuson Heartbeat.AEM wideband, HP Tuners

02-25-2021, 06:24 AM	#11
TheFlyingBananaSS Evil Genius of Chevrolet Drives: 2017 Z06, 2019 XTS, 2013 SS Join Date: Feb 2017 Location: New York Posts: 3,260	Wow. Just WOW. __________________ GPI SS2 VVT cam, ECS Novi 1500 supercharger, Corsa Extreme, Detroit Speed and BMR suspension, Circle D triple disc, Melling oil pump, LS2 chain tensioner, ATI 10% UD, DSX E85 kit, High Energy coils, BTR springs, LS2 Lifter trays, Titanium retainers, hardened push rods, FIC 1000 injectors, ZL1 pump, Mighty Mouse catch can, AEM gauges, Tial BOV, Richmond 3.91 gears, Custom gauge bezels, Speed Engineering headers, Stainless Works HF cats, DSX Aux pump, 710rwhp on E85.

02-24-2021, 05:36 PM	#4
MericanMuscle Drives: Chevy Camaro SS Join Date: Feb 2021 Location: Utah Posts: 11	Wonder if your fuel pump is crapping out?

02-24-2021, 09:21 PM	#6
EJSS Drives: 2010 Camaro SS L99 Join Date: May 2019 Location: New Orleans Posts: 119	Update: Ran the car through an entire "drive cycle" and all tests came back as "passed" except for o2 sensors and catalyst. O2 sensors / fuel trims seem to be fine on live data. On my way to the gym just now, I had my windows down and heard what sounded like bees in a tin can directly under me. My first thought is probably these cheap ass JBA cats.. kind of strange that they'd have such a huge impact on the performance though.. I guess some of the honeycomb material broke loose and is blocking flow? Figures I hear bees in my honeycomb... anyway, I'm going to take the cats off and inspect and I'll report back.

02-25-2021, 12:00 AM	#7
EJSS Drives: 2010 Camaro SS L99 Join Date: May 2019 Location: New Orleans Posts: 119

02-25-2021, 07:14 AM	#12
Aqua Blue RS/SS Drives: ABM #93 Join Date: Oct 2018 Location: Lotaburger Posts: 2,695	Yep that’ll do it. __________________ ABM #2399 2SS/RS:SOLD ABM #93 2SS/RS Black Rally stripes, Titanium Interior 4,000 miles: GM GFX side skirts and diffuser waiting on paint, GM dovetail, GM heritage, RPI ZL1 style splitter. ‘87 IROC-Z Iroc blue. all original unmolested with 50K miles.

02-25-2021, 07:34 AM	#13
102SS waiting at the tree Drives: SIM 2010 2SS/RS A6 Join Date: Apr 2013 Location: Niagara Falls Posts: 3,144	Glad you got it figured out. __________________ 2010 2SS/RS A6 ZL1 Rims 60ft 2.03 13.08 at 107.82 (4/28) 2009 Pontiac G8 3.6L the DD

02-25-2021, 07:59 AM	#14
1JEWLDSSRS Drives: 2011 SS-RS Join Date: May 2011 Location: FLORIDA Posts: 11,442	Wow!! Never seen cats look like that before!! Glad you figured that out. Wow... __________________ TSP STAGE 3 CAM,231/246 @112 LSA 614/641 LIFT, CIRCLE D 5C-4200-4500 CONVERTER,LOD INTAKE.CORSA EXHAUST. DSS 1 PC DS. PEGASUS SOLID CRADLE MOUNTS. 486RWHP/475RWTQ.LOTS MORE.