P0171 & P0174 Codes

[BeechCustom]

Hello

I took my RAV4 4.2 VVTi 2001MY into the local garage when the EML came on and the codes 'P0171' (system too lean bank 1) and P0174 (system too lean bank 2) came up.  I've had 3 of the O2 sensors replaced; Bank 2 Sensor 1 in Dec 2010, Bank 1 Sensor 1 in April 2013 and Bank 1 Sensor 2 in Dec 2013.  I did a search on this forum and it was suggested that the fault codes could be a result of dirty filament on the airflow meter.  I've got the car booked in for a minor service and the mechanic is going to clean the filament on the MAF to hopefully rectify the problem.

Does anyone have any advice on whether this is likely to do the trick.  If it doesn't, is it likely that the remaining O2 sensor (Bank 2 Sensor 2) needs replacing or could it even be one of the other o2 sensors that have been replaced in the past.

 

Many thanks.

[IanML]

MAF is certainly a possibility, another is dirty/faulty injector(s).

[BeechCustom]

Quick update.  The mechanic cleaned the MAF but the light came back on near enough straight away.  The bank 2 sensor 2 is the only o2 sensor that hasn't been replaced yet so I'm inclined to think it's that is causing the problem.  Got it booked in to be done on Thursday.