P0171 System Too Lean

[SteakAndAle]

P0171 System Too Lean (Bank 1)

Van just threw this code on the motorway. Engine doesn't seem to be any different (not obviously rough etc.) so hoping it's just a bad sensor or something.

I had also put in some fuel injector cleaner stuff, so possibly that's revealed a fault or clogged the fuel filter with gunk, or something?

Advice appreciated - on googling, I can't find any posts about this code on a Berlingo specifically..?

1.6 Petrol, btw

[cancunia]

Check the coolant temp (lean will run hot), check the spark plug electrode colour to see if white or brown. Maybe change the fuel filter in any case.

Maybe the MAF?
https://www.obd-codes.com/p0171

[SteakAndAle]

What does the spark plug electrode colour indicate? I was under the impression that a bit of brown was normal..?

Yeah I was planning to change the fuel filter anyway, no record of when it was last changed so assuming it's overdue.

Stupid question, but does the petrol Berlingo even have an MAF? I can't find any reference to it in Haynes or parts websites.

[cancunia]

What does the spark plug electrode colour indicate? I was under the impression that a bit of brown was normal..?

Yeah I was planning to change the fuel filter anyway, no record of when it was last changed so assuming it's overdue.

Stupid question, but does the petrol Berlingo even have an MAF? I can't find any reference to it in Haynes or parts websites.

Brown is normal on the plug, so if it's white it's too lean, or black is too rich. No idea about the MAF on a petrol engine, it was just what I read in the link I pasted. Looks in any case to be the oxygen sensor in the exhaust that's complaining, another possibility is maybe that's failed.

[SteakAndAle]

Ah, OK.

I cleared the code before heading home today and it didn't reappear (~140 miles). I'll change the fuel filter as planned and have a look at the lambda sensor while I'm under there anyway.