2011 cat back system an check engine light on - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Bige7171 · 06-24-2018, 02:04 PM

New guy to the site, I just purchased a 2011 camaro v-6. It has a cat back system on it. After about three days the check engine light comes on. Guy I bought it from says it needs a “spacer” in the O2 sensor. Anyone know about this, or possible soulutions? Any help is greatly appreciated.

LCPLPunk · 06-24-2018, 03:06 PM

What code does it have?

Bige7171 · 06-24-2018, 03:23 PM

P0420

LCPLPunk · 06-24-2018, 06:49 PM

Ok...did you replace the o2 sensor?

Bige7171 · 06-25-2018, 12:24 PM

No not yet, the guy said it came on three days after the system went on. I will just replace it an see. Car has 90,000 miles on it so it could be bad. I just never heard of this spacer he said they make that doesn’t allow the sensor to go all the way into the exhaust pipe.

JerTM · 06-25-2018, 12:53 PM

If it's a catback, you don't need any spacer. The cats are factory and so are the o2 readings. He sold you a car with a bad cat.

jrob56 · 06-25-2018, 12:55 PM

Quote:

Originally Posted by Bige7171

No not yet, the guy said it came on three days after the system went on. I will just replace it an see. Car has 90,000 miles on it so it could be bad. I just never heard of this spacer he said they make that doesn’t allow the sensor to go all the way into the exhaust pipe.

Sounds like a way to trick the rear o2s into thinking the cats are working when you remove or have high flow cats installed by pulling sensor out of the exhaust stream. If only mod is a catback should not be needed.

Some of the newer app code readers allow you to log the signal on the o2s and see if they are working like they should. Probably start with that or just replace the o2.

How close is the catback connection to the rear o2s on the 5th gen? Mostly a 4th gen guy learning the platform, looking at getting a 1le in next year or 2.

qcman · 06-25-2018, 01:36 PM

To me catback means the system is replaced behind the cats. In other words the O2's should not be affected in any way. It makes me think he did something more than that to the car? Or there is something else wrong and that was just an excuse........

xc_SS/RS · 06-25-2018, 02:01 PM

Quote:

Originally Posted by Bige7171

New guy to the site, I just purchased a 2011 camaro v-6. It has a cat back system on it. After about three days the check engine light comes on. Guy I bought it from says it needs a “spacer” in the O2 sensor. Anyone know about this, or possible soulutions? Any help is greatly appreciated.

you have either no cats/test pipes or highflow cats. the p0420 is a catalyst efficiency code which means your cats aren't working enough per the computer. i'd try o2 sensor foulers/spacers or get the car tuned and have those DTC codes tuned out.

alternatively you could have stock mid-pipes installed

Welker2 · 06-25-2018, 02:12 PM

Quote:

Originally Posted by JerTM

If it's a catback, you don't need any spacer. The cats are factory and so are the o2 readings. He sold you a car with a bad cat.

Agree ^^^^
Installing a Cat or Axel back exhaust will have no effect on the O2 readings. The person who sold you the car knows this and sold it to you with at least one bad cat.

Bige7171 · 06-25-2018, 04:15 PM

Great. Well I know their are cats that are coming off the manifolds by the firewall, I saw the o2 sensors there, is there 02 sensors and or cats past the ones at the firewall?

Bige7171 · 06-26-2018, 11:07 AM

Anyone?

Welker2 · 06-26-2018, 11:11 AM

Not sure if this helps or not, but there should be two sets of two O2 sensors; one pre-cat and post-cat on each side of the exhaust. Not sure where they are physically located in reference to the firewall (haven't been under my car and really looked for the sensors).

Aaron0731 · 06-26-2018, 11:24 AM

I have both stock cats I’d sell you. My car is a 2010 SS so I’m not sure if they’d work for you or not, but if so let me know and I’ll get em shipped out.

06-24-2018, 02:04 PM	#1
Bige7171 Drives: 2011 Join Date: Jun 2018 Location: Ohio Posts: 16	2011 cat back system an check engine light on New guy to the site, I just purchased a 2011 camaro v-6. It has a cat back system on it. After about three days the check engine light comes on. Guy I bought it from says it needs a “spacer” in the O2 sensor. Anyone know about this, or possible soulutions? Any help is greatly appreciated.

06-24-2018, 03:06 PM	#2
LCPLPunk USA-1 Drives: 2010 Camaro SS L99 Join Date: Jul 2016 Location: Near DC Posts: 1,893 View My Garage	What code does it have? __________________ "A Camaro in the garage is safe, but that's not what Camaros are built for..." R2C CAI / Apex Scoop / VMAX Ported TB / Speed Engineering LTHs / X-pipe / GPI port/rod-mod intake manifold / Circle D 3200 278mm Converter / 3.91 gears / DynoSteve tuned / 1LE Shocks/Struts/Toe Links / ZL1 Rear Sway Bar / Z/28 Trailing arms / Prothane Radius Arm & Subframe Bushings / BMR UCA Bracket, Steering rack bushing / B&M Tranny Cooler / RX Catch Can / Jannetty Tranny Dipstick / 2012+ Heater Hose / 2013+ Rearview Mirror / Fuel rail flip / Drake shifter / Oil Cooler Delete

06-24-2018, 06:49 PM	#4
LCPLPunk USA-1 Drives: 2010 Camaro SS L99 Join Date: Jul 2016 Location: Near DC Posts: 1,893 View My Garage	Ok...did you replace the o2 sensor? __________________ "A Camaro in the garage is safe, but that's not what Camaros are built for..." R2C CAI / Apex Scoop / VMAX Ported TB / Speed Engineering LTHs / X-pipe / GPI port/rod-mod intake manifold / Circle D 3200 278mm Converter / 3.91 gears / DynoSteve tuned / 1LE Shocks/Struts/Toe Links / ZL1 Rear Sway Bar / Z/28 Trailing arms / Prothane Radius Arm & Subframe Bushings / BMR UCA Bracket, Steering rack bushing / B&M Tranny Cooler / RX Catch Can / Jannetty Tranny Dipstick / 2012+ Heater Hose / 2013+ Rearview Mirror / Fuel rail flip / Drake shifter / Oil Cooler Delete

06-26-2018, 11:11 AM	#13
Welker2 Ret AF, cancer survivor Drives: 2013 Camaro 2SS/RS & 2006 Corvette Join Date: Jul 2015 Location: Mesquite, NV Posts: 2,741 View My Garage	Not sure if this helps or not, but there should be two sets of two O2 sensors; one pre-cat and post-cat on each side of the exhaust. Not sure where they are physically located in reference to the firewall (haven't been under my car and really looked for the sensors). __________________

06-24-2018, 03:23 PM	#3
Bige7171 Drives: 2011 Join Date: Jun 2018 Location: Ohio Posts: 16	P0420

06-25-2018, 12:24 PM	#5
Bige7171 Drives: 2011 Join Date: Jun 2018 Location: Ohio Posts: 16	No not yet, the guy said it came on three days after the system went on. I will just replace it an see. Car has 90,000 miles on it so it could be bad. I just never heard of this spacer he said they make that doesn’t allow the sensor to go all the way into the exhaust pipe.

06-25-2018, 12:53 PM	#6
JerTM Drives: 2011 2SS/RS M6 Join Date: Oct 2015 Location: Utah Posts: 1,940	If it's a catback, you don't need any spacer. The cats are factory and so are the o2 readings. He sold you a car with a bad cat.

06-25-2018, 01:36 PM	#8
qcman Drives: 2013 Camaro 2SS RDP Tuned L99 Join Date: Apr 2013 Location: Ottawa, Canada eh? Posts: 1,889	To me catback means the system is replaced behind the cats. In other words the O2's should not be affected in any way. It makes me think he did something more than that to the car? Or there is something else wrong and that was just an excuse........

06-25-2018, 04:15 PM	#11
Bige7171 Drives: 2011 Join Date: Jun 2018 Location: Ohio Posts: 16	Great. Well I know their are cats that are coming off the manifolds by the firewall, I saw the o2 sensors there, is there 02 sensors and or cats past the ones at the firewall?

06-26-2018, 11:07 AM	#12
Bige7171 Drives: 2011 Join Date: Jun 2018 Location: Ohio Posts: 16	Anyone?

06-26-2018, 11:24 AM	#14
Aaron0731 Drives: 2010 2SS/RS L99 Join Date: Oct 2015 Location: Fort Wayne, IN Posts: 295	I have both stock cats I’d sell you. My car is a 2010 SS so I’m not sure if they’d work for you or not, but if so let me know and I’ll get em shipped out.