Fault Codes Help!
06-01-2023, 01:36 PM
#1
Rennlist Member
Thread Starter
Fault Codes Help!
Anybody familiear with these 2 codes that frequently are popping up? My Duremetric displayed these codes.
I have cleared them before, but they return intermittently.... usually only throws the code during idleing for prolonged time (~3-5 min) and when engine is warmed up.
Absolutely no misfires or problems noticed with driving. O2 sensors are only about 1-1/2 years old. OEM Cats do have about 175K miles on them.
Fault codes seem contradictory to each other? one says too rich.. while other says... too lean. Before I think about even replacing Cats... I need to know if thats the issue?
any suggestions? Thanks all!
P 2198 O2 Sensor Signal Biased / Stuck Rich Bank 2 sensor 1
P 2272 Oxygen Sensor Signal behind Cat. Converter, Bank 2 too lean
I have cleared them before, but they return intermittently.... usually only throws the code during idleing for prolonged time (~3-5 min) and when engine is warmed up.
Absolutely no misfires or problems noticed with driving. O2 sensors are only about 1-1/2 years old. OEM Cats do have about 175K miles on them.
Fault codes seem contradictory to each other? one says too rich.. while other says... too lean. Before I think about even replacing Cats... I need to know if thats the issue?
any suggestions? Thanks all!
P 2198 O2 Sensor Signal Biased / Stuck Rich Bank 2 sensor 1
P 2272 Oxygen Sensor Signal behind Cat. Converter, Bank 2 too lean
Last edited by gcbpt; 06-01-2023 at 01:38 PM.
06-01-2023, 08:53 PM
#2
It appears that Sensor 1 (up stream aka the controlling sensor) is detecting a rich exhaust and telling the ECM to lean out bank 2 to compensate. Because the bank 2 true air-fuel ratio is overly lean the Cat is not able to absorb & store the oxygen and is instead releasing it out the Cat. The Sensor 2 after the Cat detects the oxygen out of the cat and that's what is causing the second P2272 code.
A Cat is detected as bad when the sensor after the Cat detects similar air-fuel fluctuations as the sensor before the Cat. Usually the after-Cat sensor is measuring a flat 0.7V or so and it doesn't fluctuate much. The after-Cat sensor output will be around 0V (lean) if you're going down hill with your foot off the gas or some other driving condition that has the fuel injectors cut off.
That before-Cat Sensor-1 may just be bad and causing the engine to think it's running rich. You could try swapping bank-1 sensor-1 with bank-2 sensor-1 to see if the problem changes to bank-1. If you had a real problem causing the engine to run rich like a leaky fuel injector then you would see excessive white smoke out the tail pipe similar to what you seen when the engine is first started cold... smoke like it's a cool winter morning even though it's a warm day. If you were running rich then your bank-2 catalytic converter would be measurably hotter than your bank-1 because the cat would be burning up that extra fuel.
A Cat is detected as bad when the sensor after the Cat detects similar air-fuel fluctuations as the sensor before the Cat. Usually the after-Cat sensor is measuring a flat 0.7V or so and it doesn't fluctuate much. The after-Cat sensor output will be around 0V (lean) if you're going down hill with your foot off the gas or some other driving condition that has the fuel injectors cut off.
That before-Cat Sensor-1 may just be bad and causing the engine to think it's running rich. You could try swapping bank-1 sensor-1 with bank-2 sensor-1 to see if the problem changes to bank-1. If you had a real problem causing the engine to run rich like a leaky fuel injector then you would see excessive white smoke out the tail pipe similar to what you seen when the engine is first started cold... smoke like it's a cool winter morning even though it's a warm day. If you were running rich then your bank-2 catalytic converter would be measurably hotter than your bank-1 because the cat would be burning up that extra fuel.
The following users liked this post:
gcbpt (06-02-2023)
06-02-2023, 09:32 AM
#3
Rennlist Member
Thread Starter
It appears that Sensor 1 (up stream aka the controlling sensor) is detecting a rich exhaust and telling the ECM to lean out bank 2 to compensate. Because the bank 2 true air-fuel ratio is overly lean the Cat is not able to absorb & store the oxygen and is instead releasing it out the Cat. The Sensor 2 after the Cat detects the oxygen out of the cat and that's what is causing the second P2272 code.
A Cat is detected as bad when the sensor after the Cat detects similar air-fuel fluctuations as the sensor before the Cat. Usually the after-Cat sensor is measuring a flat 0.7V or so and it doesn't fluctuate much. The after-Cat sensor output will be around 0V (lean) if you're going down hill with your foot off the gas or some other driving condition that has the fuel injectors cut off.
That before-Cat Sensor-1 may just be bad and causing the engine to think it's running rich. You could try swapping bank-1 sensor-1 with bank-2 sensor-1 to see if the problem changes to bank-1. If you had a real problem causing the engine to run rich like a leaky fuel injector then you would see excessive white smoke out the tail pipe similar to what you seen when the engine is first started cold... smoke like it's a cool winter morning even though it's a warm day. If you were running rich then your bank-2 catalytic converter would be measurably hotter than your bank-1 because the cat would be burning up that extra fuel.
A Cat is detected as bad when the sensor after the Cat detects similar air-fuel fluctuations as the sensor before the Cat. Usually the after-Cat sensor is measuring a flat 0.7V or so and it doesn't fluctuate much. The after-Cat sensor output will be around 0V (lean) if you're going down hill with your foot off the gas or some other driving condition that has the fuel injectors cut off.
That before-Cat Sensor-1 may just be bad and causing the engine to think it's running rich. You could try swapping bank-1 sensor-1 with bank-2 sensor-1 to see if the problem changes to bank-1. If you had a real problem causing the engine to run rich like a leaky fuel injector then you would see excessive white smoke out the tail pipe similar to what you seen when the engine is first started cold... smoke like it's a cool winter morning even though it's a warm day. If you were running rich then your bank-2 catalytic converter would be measurably hotter than your bank-1 because the cat would be burning up that extra fuel.
THANK YOU so much for your thoughts and suggestions! I so appreciate your help!!
I was first possibly thinking maybe a vacuum leak but I guess that would cause Sensor 1 to detect a overly 'lean' exhaust ..right?
06-02-2023, 02:30 PM
#4
In your case it could be something bad happening on Bank 2 like a leaky fuel injector - which is really bad considering it will cause bore scoring. That would be my biggest concern.
06-04-2023, 09:41 PM
#5
Rennlist Member
Thread Starter
Thank you again for your comments...
as a side note... the Engine has only about 12k miles on it... its a new completely rebuilt 4.0L from Jake Raby - Flat 6 Innovations.
Its a beast of engine... so smooth and pulls like crazy.
The cats have about 175k miles on them.... car threw Cat Insufficiency codes P0420/0430 several months ago... I cleared them and it never came back.. however now these O2 Sensor codes have popped up a few times now... never while driving and only when its been hot and idling for a prolonged time.
So... im thinking the cats are probably on their way out... and I might have a bad 02 sensor as well like you initially said (even though they are new. ( I replaced all 4 at same time as engine)
as a side note... the Engine has only about 12k miles on it... its a new completely rebuilt 4.0L from Jake Raby - Flat 6 Innovations.
Its a beast of engine... so smooth and pulls like crazy.
The cats have about 175k miles on them.... car threw Cat Insufficiency codes P0420/0430 several months ago... I cleared them and it never came back.. however now these O2 Sensor codes have popped up a few times now... never while driving and only when its been hot and idling for a prolonged time.
So... im thinking the cats are probably on their way out... and I might have a bad 02 sensor as well like you initially said (even though they are new. ( I replaced all 4 at same time as engine)
06-04-2023, 10:56 PM
#6
Three Wheelin'
You have a small air leak very close to the post cat sensor on bank 2. It could be a crack in the O2 sensor bung, or a loose O2 sensor that is not tight. That small amount of air causes the O2 sensor to see more oxygen than it is supposed to and it is stuck in the oxygen rich mode (which the computer interprets as stuck LEAN). Once it sees that, the ECU may do some correction to the mixture to see if it can compensate which causes the front o2 sensor to go rich.
Find that leak near the rear O2 sensor and fix that first, then run it again.
Find that leak near the rear O2 sensor and fix that first, then run it again.
06-05-2023, 09:19 AM
#7
Racer
Do yourself a favour and get yourself a smoke gizmo like AutoLine Pro. Not expensive, easy to use and will likely save you many dollars buying needles new parts…..personal experience!
cheers,
Johan
cheers,
Johan
