Incorrect AFR at WOT Help!!

[AJP turbo]

Ok well reason I ask about age is because it could be 6 years old  now based on when it was built and the o2's are subject to constant high heat because they are inches from turbos and with stock tunes these cars run much leaner than I would guess which only increase egt.

These tunes go into fuel enrichment very late under boost which is odd to me but apparently u can get away with it because of being direct injected and I've read the piston design helps alleviate preignition.....but the good thing about commanding fuel enrichment late is it lowers fuel consumption while at wot

[AJP turbo]

Yeah I would think some sort of slow response codes...so I dunno why u don't get them....and ur O2 should read nearly identical which they don't

[ZSHO]

I'm not exactly sure on this but codes are set if the sensor cant get above a calibrated rich or lean voltage prior to a calibrated time out period,this time out period must happen 3 times in a row to set a fault,if it does not happen 3 times in a row no codes will be set,so basically its like baseball three strikes and your out(code) Guess thats the reason for the delayed resonse.  Z

[SHOdded]

Another reason to go WOT 3+ times in the next datalog

[AJP turbo]

Change your bank 2 Primary(upstream) oxygen sensor and be done with it. You would be well served to use an OEM exact replacement. I think ford uses NTK sensors. Oxygen sensors may not be the same as far as the Lambda vs voltage scale so it's important to have sensors that match. It won't be cheap but the primary o2 sensors are very important.

The only thing I can't figure out in your tuned WOT log is why your stft in bank 2 isn't going crazy when reading .99 lambda when bank 1 is reading .80 it must have something to do with the logic in the ECU and how fuel trims are applied

Maybe another member can tell you which is bank 2. I don't know off the top of my head.. But that sensor is your problem. If you have a leak in your turbo inlet or charge piping that won't show in stft's because that air hasn't been metered. And as far as exhaust leaks, you can see that in stft's and measured afr but I've never seen that flat line a 02 sensor reading.

Change that sensor and report back.

[AJP turbo]

Another quick thing: In your tuned WOT log it looks obvious to me that your bank 2 sensor is bad. Bank 1 looks normal.

But in your stock WOT log bank 1 and bank 2 display the same dysfunctional thing. They just don't do it at the same time. Tune is out of the equation since this is the stock log. Your LAMBSE at 139 seconds is .82 and richer and both 02's are reading 1.0 and both stft's are 1.0 which basically is telling me that it's not using o2 feedback and not making corrections anymore at that point. So it must just be strictly fueling from the MAP sensor and other lookup tables. And maybe you aren't getting any DTC's because when you lift your sensors start reading correctly....Basically they check out for a minute then come back maybe not triggering the DTC's.

If it were me I'd change both...I said previously Just bank 2 but now I say both.

[SHOdded]

The O2 sensors are not that expensive, just the bank 1 sensors are somewhat of a pain to get to being stuck between firewall & engine.

At the very least, I'd do bank 2, and if that doesn't clear up the issues, go for bank 1 as well.

[kskrew4life]

Another reason to go WOT 3+ times in the next datalog

4 TO 5 WOT sessions in this log, and looked like bank 2 stayed 0.00 after the second wot.. still no DTC.... im a bit worried my pcm might be going since its not throwing a fault, or the equation in the pids for these afr values are wrong

[kskrew4life]

Another quick thing: In your tuned WOT log it looks obvious to me that your bank 2 sensor is bad. Bank 1 looks normal.

But in your stock WOT log bank 1 and bank 2 display the same dysfunctional thing. They just don't do it at the same time. Tune is out of the equation since this is the stock log. Your LAMBSE at 139 seconds is .82 and richer and both 02's are reading 1.0 and both stft's are 1.0 which basically is telling me that it's not using o2 feedback and not making corrections anymore at that point. So it must just be strictly fueling from the MAP sensor and other lookup tables. And maybe you aren't getting any DTC's because when you lift your sensors start reading correctly....Basically they check out for a minute then come back maybe not triggering the DTC's.

If it were me I'd change both...I said previously Just bank 2 but now I say both.

thanks for taking the time out to look into these logs ajpturbo, the Next log i post here will be after a new o2 has been installed

[kskrew4life]

I'm not exactly sure on this but codes are set if the sensor cant get above a calibrated rich or lean voltage prior to a calibrated time out period,this time out period must happen 3 times in a row to set a fault,if it does not happen 3 times in a row no codes will be set,so basically its like baseball three strikes and your out(code) Guess thats the reason for the delayed resonse.  Z

I tried out your suggestions did maybe 6 or 7 wot and still no DTC or anything funny with the car...

[AJP turbo]

ECU failure very rare......Throw in your new sensors . Don't overthink it....It could be 1000 reasons why no DTC

[AJP turbo]

Id change both.....Even the sensor in bank 1 that seems to be reading correctly does not match LAMBSE and it should.

[ZSHO]

I agree with everyone above on this matter,especially the 02 sensors playing such an important role in your vehicles performance capabilities,why not change them asap especially if you plan on keeping the car,it will thank you later,especially with the current mileage on there,best of luck and keep us updated.  Z

[SHOdded]

Wonder if it takes sustained WOT (like in the earlier datalogs) to set.  The latest runs at full throttle are usually no more than a second or two in duration.

[Txstrmhntr]

I had a similar issue with my bank 2 sensor, then it quit working entirely since replacing it everything is fine again.

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