Volvo v70 help - 1998 AWD Vacuum line

[erikv11]

Everything you need to know about vacuum lines, including great pictures if the nipple on the intake manifold.

here viewtopic.php?t=63615
and here viewtopic.php?f=1&t=65002 (this is for non-turbos but has very good IM pics).

[GunnerCG20]

Okay ya'll were right found a clipped of vacuum line under that water hose on the top passenger side!. Car is running better but will still die out after a minute or two of idling. After it warms up it will drop to 400 to 500 RPM and then go back to around 1000. Still throwing a P0171 too lean error. I can't see any other leaks. If I unplug the MAF sensor it will idle just fine around 1100. Do I still have an air leak or is it the MAF? Local O'Reily's can't test a MAF. Thoughts? Thanks for all your help so far!

[erikv11]

... If I unplug the MAF sensor it will idle just fine around 1100. Do I still have an air leak or is it the MAF? ...

Almost certainly the MAF is bad. Only Bosch on this part, and no remans, otherwise you will only see more MAF headaches. I would highly recommend sourcing from a junkyard or post a wanted ad in the for sale section here, there are a ton of perfectly good, used ones kicking around. You can drive it around a few days with the MAF unplugged, and I would recommend that to see if it stays "solved" with the MAF unplugged.

Many of the 20 year old rubber vacuum lines may be falling apart now. Consider replacing them all as per the link I posted above.

[RickHaleParker]

P0171 = EFI-231 or EFI-232 Long-term fuel trim.

Diagnostic trouble code (DTC) information EFI-231, EFI-232
EFI-231 Long-term fuel trim, part load
EFI-232 Long-term fuel trim, idling speed

A2301157 Condition
The engine control module (ECM) receives information from the heated oxygen sensor (HO2S) about the fuel/air mixture in the idling and partial load ranges. If the fuel/air mixture deviates from λ=1 the short-term fuel trim will compensate for this by adjusting injection time so that λ=1 is achieved. When the short-term fuel trim makes an adjustment, the integrator median must be adjusted by the long-term trim. If adaptation needs to adjust to close to its maximum diagnostic trouble code (DTC) EFI-232 (idling range -0.48 ms - 0.40 ms) or diagnostic trouble code (DTC) EFI-231 (part load range factor 0.773 - 1.227) and the status message Upper limit (lean fuel/air mixture) or Lower limit (rich fuel/air mixture) will be stored.

Substitute value
none.

Possible source
Upper limit:

• defective mass air flow (MAF) sensor
  low fuel pressure
  air leakage
  faulty sensor signals.

Lower limit:

• defective mass air flow (MAF) sensor
  high fuel pressure
  leaking injectors
  leaking evaporative emission (EVAP) system
  contaminated engine oil
  oil level too high
  faulty sensor signals.

Fault symptoms
can result in high fuel consumption
may result in poor performance.