Hello all, about every 2 days i get an EML light come on my s/c with the pcodes being
P0174 - system too lean bank 2
P0172 - system too lean bank 1
And somtimes this one aswel
P0420 - catalyst system efficiency below threshold bank 1

I have had a listen for air leaks with nothing obvious, clean the throttle body and ran some BG44K through the system.

Seams to drive normal with the light on. It never used to do it just the past couple of months or so. It was serviced with the plugs changed about 8000miles ago, not sure on the service schedule for plugs on these to be honest.

Any ideas???

90000 miles for the plugs make sure the oil filler is secure and also the fuel tank cap as this can effect the system as i was getting them a lot whilst running on gas in mine so made sure they were tight and no more codes since may not be your issue but its a cheap starter to be getting on with

Ahh intresting. I have no oil leak on it but will check the filter any way. Was the seal split on the cap then?
9000miles for plugs, there due again then!! Maby that might be a cause
Thanks for the reply i will get checking

90,000 miles, not 9,000

Well if you get desperate.
Unplug the air meter.
Turn the ignition on fir 5 seconds.
Plug meter back in.

This should reset the learning

Was there not an issue with high miles S/Cs of the MAF getting dirty/ an oil film on the sensor and cleaning it solved this problem? I am probably wrong on this but i’m Sure that there was a post either here or on FullFatRR about these codes and the cause was as above 2020 Pangea Green 1st Edition D240 New Defender 110 is here and loving it
2018 Melting Silver Mini Countryman PHEV - soon to be replaced
2015MY Corris Grey SDv6 HSE Dynamic, the best car I have ever owned, totally reliable only a cou0le of rattles in 3 years, now no longer in my care
Also in my garage is a 1996 TDi300 Defender 90 County HT made into a fake CSW

I would suggest you don't clean the MAF sensor until you are sure / do research.


Very easy to break them.


Although these probably have the robust version.