Second o2 sensor slow

BG1988

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Does anyone have any information of the O2 sensor
I suspect my is slow like super Slow out of a deceleration fuel cut off.....this causes Check engine Light for the second Bank 2 catalytic converter P0430(typically P0420 is the common one when there is a failure aka bank 1)


it's pretty stable at 0.865 to 0.895 but after a DFC it's slow to move from 0.1v unless i give it more gas
sensor 1 jumps all over the place from 0.1 to 0.870

they're not "following"

I end up with a "false flag CEL" · Short Term Fuel Trim (STFT) of +34.5 on both banks...

when running the Long term fuel trim is 3 to 4 range when driving
 
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Fless

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Swap the sensors left to right (or between equivalent sensors) and see if the code and sluggishness follow. Likely time for new O2 sensors.
 

OR VietVet

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How many miles is on the vehicle/sensors? IMO, any time after 100k miles, the maintenance on these sensors requires all 4 replacement, to help protect the catalytic converters.
 

swathdiver

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Does anyone have any information of the O2 sensor
I suspect my is slow like super Slow out of a deceleration fuel cut off.....this causes Check engine Light for the second Bank 2 catalytic converter P0430(typically P0420 is the common one when there is a failure aka bank 1)


it's pretty stable at 0.865 to 0.895 but after a DFC it's slow to move from 0.1v unless i give it more gas
sensor 1 jumps all over the place from 0.1 to 0.870

they're not "following"

I end up with a "false flag CEL" · Short Term Fuel Trim (STFT) of +34.5 on both banks...

when running the Long term fuel trim is 3 to 4 range when driving
It's not your sensor, the cat is dead; unless you have an exhaust leak on that side.
 
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BG1988

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It's not your sensor, the cat is dead; unless you have an exhaust leak on that side.
I used M4 I was able to do a drive cycle, all drive monitors are complete in 9 miles, now including the infamous "GM Evap monitor "...


obvious it's an DFCO issue then a Cat issue.. since DFCO is 'off' in M4 as well as the AFM




according the the Diagnostics sheet HO2S2 Post o2 sensor(Sensor2 ) ≥101 mV for 2.50 seconds prior to a DFCO exit... that is an enable condition

if my second sensor is dropping to a random "DFCO event " while my Bank1sensor2 is not then must be an issue with the sensor it self i'm going to replace all 4 of them the suv has 109k on it...
 
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BG1988

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deceleration fuel cut off the PCM has an aggressive version of DFCO to save a few drops of fuel and a even more aggressive version of AFM.... remember it can accelerate in afm
 
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BG1988

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a broken cat would have been reviled when i did a drive cycle with DFCO off
as i would have gotten the P0430 again before the drive cycle completed

maybe it just needed the italian tune-up i was running the engine at 3500-4000rpm for several miles... Yes the engine was warmed up before doing that
 

OR VietVet

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a broken cat would have been reviled when i did a drive cycle with DFCO off
as i would have gotten the P0430 again before the drive cycle completed

maybe it just needed the italian tune-up i was running the engine at 3500-4000rpm for several miles... Yes the engine was warmed up before doing that
We used to call those an "Arkansas Tune Up".
 

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