CEL(O2 Sensor) After Switch Tune

current mod

- APR Intake Front/Rear
- APR Intercooler
- APR Downpipe with Rear o2 Sensor
- Borla Catback Exhaust
- DV+


i had APR Tune without any CEL But after i switch to Stratified Tune im having
- P2271(o2 Sensor Signal Stuck Rich; Bank 1 Sensor 2
- P013A ( o2 Sensor Slow Response - Rich to Lean)
- P2096 ( Post Catalyst Fuel Trim System Bank 1 Too Lean)
- P2196 ( 02 Sensor Signal Stuck Rich Bank 1 Sensor 1)


this is what i have on Cobb Accessport.

Stratified told me contact APR but Local APR Dealer Told its Stratified Tune Fault Because there was no CEL During APR Tune. and local APR Dealer want $109 for Looking into my car

anyone know what will be reason for those CEL, im sure its about Downpipe o2 Sensor but want to know the exact Reason before going to APR Dealer

you have a way smaller (or none at all) catalytic converter on that downpipe. APR stg 2 tune turns off the associated O2 sensor to stop those codes, because its getting WAY more exhaust than it did stock. Stratified doesnt do that so you either need to get some spacers for your O2 sensors or go back to the APR tune.

I know what I'd do APR's way quicker lol

Stratified has turned off several codes for me relating to emissions and my runner flap delete. They should have no problem turning off the code for you like APR does.

zef said:

Stratified has turned off several codes for me relating to emissions and my runner flap delete. They should have no problem turning off the code for you like APR does.

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x2 I remember them asking if I wanted them to disable o2 sensor with the tune when I submitted my form


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Not sure what PA's annual auto inspection entails, but you may want to consider that if you choose to have them turn off the sensors. In Texas, at least one of the O2 sensors has to be "ready". With the stage II APR tune they are both "not ready" unless you put it back to stock mode, which will in turn cause a CEL. I went with a spacer on one of the C02 sensors and its worked fine ever since.

Lazer 100 said:

Not sure what PA's annual auto inspection entails, but you may want to consider that if you choose to have them turn off the sensors. In Texas, at least one of the O2 sensors has to be "ready". With the stage II APR tune they are both "not ready" unless you put it back to stock mode, which will in turn cause a CEL. I went with a spacer on one of the C02 sensors and its worked fine ever since.

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Yeah I ran a downpipe with no tune for awhile and had a spacer on the o2 sensor. Didn’t have a CEL pop up unless I went WOT a few times. Planning on flashing to stock with the spacer to get past emissions. Now to try and get them to ignore my 15% tint......


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pdan said:

Yeah I ran a downpipe with no tune for awhile and had a spacer on the o2 sensor. Didn’t have a CEL pop up unless I went WOT a few times. Planning on flashing to stock with the spacer to get past emissions. Now to try and get them to ignore my 15% tint......


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Leave your sunroof shade open and go when its sunny. It'll seem brighter inside.