Trouble Codes P0172 and P1171

Uliston · Post by **Uliston** » 18 Nov 2010, 09:45

P0172 = system too rich and P1171 = long term fuel trim? The car is a 2001 V70 2.4T with 120K miles. I have cleaned the MAF sensor, cleaned the throttle body, and checked for vacuum leaks with no luck. Both O2 sensors were replaced last year. Is there anything else I should try checking, or should I try a new MAF sensor? Is there a way to check or test the MAF sensor before replacing it? Thanks for the help!

Post by **MadeInJapan** » 20 Nov 2010, 22:35

How does the car drive? Usually if it's the MAF your car will stumble and go into "limp mode." If this is not the case, I would check and recheck for leaks, even small leaks. It could be a turbo hose and not vacuum lines as well, so check those- one might have a crack in it or slipped partially off (typically the one under the radiator). Also, what type of 02 sensors did you replace with? Was the problem the same before and after the replacement?

Post by **JRL** » 21 Nov 2010, 06:47

Aftermarket 02 sensors do not match up well with Volvos
If you did not use VOLVO 02 sensors you may need to replace them again

Post by **MadeInJapan** » 21 Nov 2010, 09:46

^^^^^ Agreeed

Retired MVS Contributor · Post by **Retired MVS Contributor** » 21 Nov 2010, 12:13

P0172=
List of errors for: ECU ECM with code 262A
ECM-262A Long-term fuel trim, idling. Lower limit
ECM-262A Long-term fuel trim, idling. Upper limit
ECM-262A Long-term fuel trim. Lower limit
ECM-262A Long-term fuel trim. Upper limit

P1171=
List of errors for: ECU ECM with code 261A
ECM-261A Fuel pressure system. Faulty signal
ECM-261A Fuel pressure system. Signal too high
ECM-261A Fuel pressure system. Signal too low
ECM-261A Long-term fuel trim. Lower limit
ECM-261A Long-term fuel trim. Upper limit

From BSR PPC diagnostics

Uliston · Post by **Uliston** » 23 Nov 2010, 08:23

Thanks guys for your responses. Dang, I did not know that about the aftermarket o2 sensors. I used Bosch sensors. Will I have to go to the dealer to get Volvo o2 sensors or is there a good place to get them on-line?

The car seems to run okay, except when cold. It has started getting cold here and the car is definitely sluggish in the morning when cold - won't accelerate hardly at all until it's a bit warmed up. I am a pretty tame driver and don't use the turbo much, so yesterday I thought I'd see how it was working. I put the pedal to the metal and it wouldn't kick the turbo on - it just seems to hesitate and sputter. I don't know if this is related to the codes, because the turbo has worked before and the car has thrown these same codes.

Uliston · Post by **Uliston** » 05 Jan 2011, 13:34

UPDATE: Turns out these codes were thrown as a the result of a what I think was a slowly dying MAF sensor. Changed it out and all is good now.