GEN 2 (2019) P2098

[bolands]

2019 105k keeps getting a P2098 lean on bank 2. replaced O2 sensor and spark plugs and the code went away for a couple months, now the code is back and keeps coming back after 2 key cycles. truck is stock. any ideas where to look for a vacuum leak? has anyone had this problem and what was the fix? any help would be helpful. t

 

[FordTechOne]

P2098 is post catalyst fuel trim too lean Bank 2. That is much different than a pre-catalyst lean code, which is engine performance related. Which O2 sensor did you replace and what brand did you buy?

P2098 can be caused by a faulty O2 sensor (Bank 2 sensor 2), a contaminated upstream O2 sensor, exhaust leaks, or circuit/pin fit issues in the B2S2 O2 sensor harness.

 

[bolands]

replaced B2S2 with a denso O2 sensor.

 

[Old-Raptor-guy]

Did the KAM / learned values get reset when O2 was replaced.

Seen this exact thing on a Mazda a few weeks ago. The O2 was bad, but learned values were not reset. This caused the PCM to really HATE the new O2 sensor.

Had a 6.7 PSD a few months ago with a leaking DEF injector (external leak). No lights, no codes nothing. Customers complaint was could smell something "burning "

After the repair about 20 miles down the road the truck went absolute ape shit. Warnings on, check engine on, speed limited to 50 mph.

The truck had learned to deal with the leaking injector, assuming the leak started small because when we fixed it, it was a rather large leak. The repair was instantaneous (obviously) and the PCM did NOT like the sudden change in flow rates.

Reset learned value and all was good.

This is something new that was not required 10+ years ago for most repairs so it is new to me.

Clearing codes does not reset learned values.

 

[bolands]

the KAM did not get reset when the new O2 sensor went in.

 

[R Level]

Also, lower grade fuel can pop the code(s) as well. Try better fuel!