LS3 Lean issue - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Chris111179 · 10-29-2023, 09:32 AM

Quick question, I have a 2010 with the LS3 in it. Stock tune, runs great but has recent developed two codes. One for bank one lean one for bank too lean. P0171 and P0174. Just started throwing the codes randomly on the interstate, with no noticeable change other than the engine light. I have attached some freeze frame data which indicates the long term fuel balance is very lean, the other photos and video is at idle. I have checked the lines going to the intake and they are all intact with no leaks. I sprayed around the intake with a flammable aerosol and no leaks detected. I can’t hear any appreciable exhaust leaks. Do those o2 sensor readings look ok? Thanks everyone!

Chris111179 · 10-29-2023, 09:36 AM

Quote:

Originally Posted by Chris111179

Quick question, I have a 2010 with the LS3 in it. Stock tune, runs great but has recent developed two codes. One for bank one lean one for bank too lean. P0171 and P0174. Just started throwing the codes randomly on the interstate, with no noticeable change other than the engine light. I have attached some freeze frame data which indicates the long term fuel balance is very lean, the other photos and video is at idle. I have checked the lines going to the intake and they are all intact with no leaks. I sprayed around the intake with a flammable aerosol and no leaks detected. I can’t hear any appreciable exhaust leaks. Do those o2 sensor readings look ok? Thanks everyone!

Photos attached

chevy pilot · 10-30-2023, 12:56 AM

Quote:

Originally Posted by Chris111179

Do those o2 sensor readings look ok?

Do they change up and down about between 100mV-900mV ?

Btw.I once had a leak in my LS1, in the hose a little before the pcv.Both LTFT was 25%

Chris111179 · 10-30-2023, 10:41 AM

Quote:

Originally Posted by chevy pilot

Do they change up and down about between 100mV-900mV ?

Btw.I once had a leak in my LS1, in the hose a little before the pcv.Both LTFT was 25%

I just ran a log, both cycle up and down around that area. I did just notice that the oil fill tube seems to be a little loose where it connects to the valve cover. I guess I’ll have to investigate that.

morepowerjoe · 10-30-2023, 07:24 PM

Did your weather just get really cold when it started?

Chris111179 · 10-30-2023, 08:24 PM

Quote:

Originally Posted by morepowerjoe

Did your weather just get really cold when it started?

I had the same thought. It did drop about 30-35 degrees. Possibly a little more. So I did the fuse pull thing and left it overnight. After I did about 75 miles the light came back on. Would that make the sensors recalibrate or should I be doing something else?

acutron42 · 10-31-2023, 04:58 AM

Just for the heck of it check the screws @ the maf sensor & throttle body bolts. It probably wont help but it is an easy check.

morepowerjoe · 10-31-2023, 05:44 AM

Quote:

Originally Posted by Chris111179

I had the same thought. It did drop about 30-35 degrees. Possibly a little more. So I did the fuse pull thing and left it overnight. After I did about 75 miles the light came back on. Would that make the sensors recalibrate or should I be doing something else?

I'm thinking tbat maybe your o2 sensors are really old or something along that route. Because I'm self tuned and when it the weather got cold here in Texas my car went really lean too. It's because your getting a lot more air now and not enough gas. So to fix mine I had to readjust the maf with hp tuners. Something to do as a last resort for you. So I would look into your o2 sensors or spark plugs maybe try premium fuel if you usually don't.

Chris111179 · 10-31-2023, 10:08 AM

Quote:

Originally Posted by morepowerjoe

I'm thinking tbat maybe your o2 sensors are really old or something along that route. Because I'm self tuned and when it the weather got cold here in Texas my car went really lean too. It's because your getting a lot more air now and not enough gas. So to fix mine I had to readjust the maf with hp tuners. Something to do as a last resort for you. So I would look into your o2 sensors or spark plugs maybe try premium fuel if you usually don't.

I filled up at a different station than I normally do with 93 this time, maybe ruling out bad fuel. The car does have 180K miles on it. Unknown when the last time the O2 sensors were replaced. I will give the Maf sensor another cleaning and see what that gets me.

Mouse330 · 11-01-2023, 03:07 PM

Most likely the MAF miscalculating airflow into the engine

Chris111179 · 11-01-2023, 05:55 PM

Ok, so I filled up with some fresh 93. Took off the intake and cleaned everything along with the maf sensor. Reconnected everything and checked for leaks again. This photo was after about 15 miles of driving. Long term rates look to be much better. Do you think the check engine light will still come on?

morepowerjoe · 11-01-2023, 06:00 PM

I don't know what the cutoff is by the ecm for being too lean but you'll just to wait and see. If it does I would get aone ac delco o2's and replace them and check your spark plugs.

chevy pilot · 11-02-2023, 03:40 AM

Quote:

Originally Posted by morepowerjoe

I don't know what the cutoff is by the ecm for being too lean but you'll just to wait and see.

I remember over +25.

acutron42 · 11-02-2023, 06:07 AM

Looks better but maybe it needs more history to see what way it trends? Keep an eye on it over a few drive cycles & see what happens. -10 to +10 is normal.

10-29-2023, 09:32 AM	#1
Chris111179 Drives: 2010 Camaro SS Join Date: Feb 2023 Location: NH Posts: 11	LS3 Lean issue Quick question, I have a 2010 with the LS3 in it. Stock tune, runs great but has recent developed two codes. One for bank one lean one for bank too lean. P0171 and P0174. Just started throwing the codes randomly on the interstate, with no noticeable change other than the engine light. I have attached some freeze frame data which indicates the long term fuel balance is very lean, the other photos and video is at idle. I have checked the lines going to the intake and they are all intact with no leaks. I sprayed around the intake with a flammable aerosol and no leaks detected. I can’t hear any appreciable exhaust leaks. Do those o2 sensor readings look ok? Thanks everyone!

10-30-2023, 07:24 PM	#5
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,133	Did your weather just get really cold when it started? __________________ 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

10-31-2023, 04:58 AM	#7
acutron42 Drives: 2013 Camaro 2SS AGM Join Date: Apr 2020 Location: WNY Posts: 738	Just for the heck of it check the screws @ the maf sensor & throttle body bolts. It probably wont help but it is an easy check. __________________ 2013 2SS GPI built & tuned 415, spec'd by Andrew Cammer. GPI ported intake/tb/heads, Tooley springs, CHE trunnions, Callies rotating assembly, Diamond pistons, GPI SS3 VVT, ATI 10% ud damper, Circle D 3800, Kooks ceramic coated lt's with green cats, Mishimoto rad & oil cooler, Derale trans cooler, Holley efi rails.

11-01-2023, 05:55 PM	#11
Chris111179 Drives: 2010 Camaro SS Join Date: Feb 2023 Location: NH Posts: 11	Ok, so I filled up with some fresh 93. Took off the intake and cleaned everything along with the maf sensor. Reconnected everything and checked for leaks again. This photo was after about 15 miles of driving. Long term rates look to be much better. Do you think the check engine light will still come on? Attached Images

11-01-2023, 06:00 PM	#12
morepowerjoe Drives: 2012 Chevrolet Camaro l99 Join Date: Aug 2020 Location: Austin, TX Posts: 2,133	I don't know what the cutoff is by the ecm for being too lean but you'll just to wait and see. If it does I would get aone ac delco o2's and replace them and check your spark plugs. __________________ 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

11-01-2023, 03:07 PM	#10
Mouse330 Drives: 2011 2SS, 2006 GMC Sierra Join Date: Jul 2019 Location: MA Posts: 266	Most likely the MAF miscalculating airflow into the engine

11-02-2023, 06:07 AM	#14
acutron42 Drives: 2013 Camaro 2SS AGM Join Date: Apr 2020 Location: WNY Posts: 738	Looks better but maybe it needs more history to see what way it trends? Keep an eye on it over a few drive cycles & see what happens. -10 to +10 is normal. __________________ 2013 2SS GPI built & tuned 415, spec'd by Andrew Cammer. GPI ported intake/tb/heads, Tooley springs, CHE trunnions, Callies rotating assembly, Diamond pistons, GPI SS3 VVT, ATI 10% ud damper, Circle D 3800, Kooks ceramic coated lt's with green cats, Mishimoto rad & oil cooler, Derale trans cooler, Holley efi rails.