fault code help

[dannyboy101]

I've just had the em light come on again. It threw up p0171 which is lean running.. I've just changed the maf, but think I will change it back! Any ideas what else I should do to cure this?

[deathrider311271]

P0171 ECM-262A Long-term fuel trim Upper limit

front lambda sensor mate, did you use a genuine Bosch MAF sensor??

[960kg]

I've just had the em light come on again. It threw up p0171 which is lean running.. I've just changed the maf, but think I will change it back! Any ideas what else I should do to cure this?

You don`t say which motor you have?

There are over a thousand error codes in the OBD11 book and one engine does not have all of these available.

It matters which fuel system you have to what the error code refers to!

If you tried a MAF it must be Volvo new or working 2nd hand, a cheap copy will give problems.

I have put up ME7 system and Motronic 4.4 so pick put what refers to you.

[dannyboy101]

Nope it was a cheap copy! Which I will remove and put the bosch one back. I have a pre me7 t5 if that helps the diagnostisc guys :)

[dannyboy101]

Pics are a great help thank you. What is a pulsation damper please.

Assuming the maf (i will put the orig bosch one back in) is fine, what would be my next move?

Ive brought a code reader so can record live data if this will help to see whats going on.

[960kg]

On the V70 the Fuel Pressure Regulator is moved down by the steering box area by the bulkhead and in it`s place on the fuel rail is the Pulsation Damper.

It smooths out the pressures pulses in the fuel supply to the injectors so they get a more accurate supply.

Usually with this code members on other sites have ended up with a new MAF to sort it out!

I would check all the sensor connectors for oxidisation and clean them before going onto the expensive parts.

Even a new Walbro fuel pump is a good idea from eBay. The Volvo originals are Walbro.

Good Luck

Keith