Dreaded P219B

[OldFart]

I have a 2017 Ford Expedition and had a CEL about 3 weeks ago and scanner showed P219B. Mechanic said 2 of the 3 fuel injectors on Bank 2 were bad and suggested I change all 6 since they are hard to get to, which I did. Everything has been good since then - lots more power, engine seems smoother - but this morning the P219B came back. I'm at 125k miles and will be replacing the spark plugs over the weekend. Any other recommendations on what to look at? My scanner has limited diagnostics but shows the O2 sensors "passed" whatever checks it does.

Thanks in advance...

 

[tacoduck]

I have a 2017 Ford Expedition and had a CEL about 3 weeks ago and scanner showed P219B. Mechanic said 2 of the 3 fuel injectors on Bank 2 were bad and suggested I change all 6 since they are hard to get to, which I did. Everything has been good since then - lots more power, engine seems smoother - but this morning the P219B came back. I'm at 125k miles and will be replacing the spark plugs over the weekend. Any other recommendations on what to look at? My scanner has limited diagnostics but shows the O2 sensors "passed" whatever checks it does.

Thanks in advance...

Was it a check engine light? Any other symptoms? These trucks are hard on plugs. I actually replaced my plugs with ford plugs bought from the dealership and a couple failed 1 year later. I’ve heard ford motor craft plugs had some manufacturing issues, so hopefully new plugs will fix your problem.

 

[GaryH]

Could be a vacuum leak or bad O2 sensor. Code P219b relates to a bank 2 imbalance of the air to fuel ratio.

 

[OldFart]

Yes, the check engine light came on. I used my el cheapo scanner to pull the P129B code. It is showing an O2 sensor voltage of 0.75 volts while at idle. I did install new Motorcraft plugs this weekend and the truck is driving like new. I've cleared the code so keeping my fingers crossed I won't see it again.

No obvious vacuum leaks, @GaryH If the error throws again, I'll switch the O2 sensors and see if it throws again on Bank 2 or if it switches and throws on Bank 1 (indicating the O2 sensor is the culprit). Hopefully it won't come to that, though.

I wish the error code was a bit more informative. It doesn't even tell if it's rich or lean, though it looks like mine is rich.

 

[Calman2k]

You could check the plug wires and coils too. If the plugs aren't firing right it could be the wires or coils.