1998 V70 code PO 172

Harpoon · Post by **Harpoon** » 02 Aug 2011, 11:45

JBlackburn; are you out there? I have code (PO 172/ system too rich B1) that I have reset about 5 times. I have cleaned the MAF, changed plugs, changed plug wires, coil, changed air cleaner, replaced temp sensor. Could this mean I need a new cap and rotor? I am also aware of a leak in my heater core. Could losing a small amount of coolant (not noticeable on temp gauge) be causing the computer to enrich the fuel so as not to overheat the vehicle?
I would greatly appreciate any advice/suggestions. Thank you in advance to all who offer up ideas/help.

Post by **vjaneczko** » 02 Aug 2011, 11:52

Sounds like a vacuum leak:
https://www.matthewsvolvosite.com/forums ... php?t=6283

Probably a good idea to look into replacing all of the hoses & elbows 'cause it sounds like you're in the middle of a Stage 0 - might as well continue the effort!
https://www.matthewsvolvosite.com/2009/0 ... s-stage-0/

Post by **jblackburn** » 02 Aug 2011, 12:20

95% chance it's the vaccum elbow at the left side of the intake manifold.

I fixed it with a small piece of flexible tubing to connect the two lines.

Harpoon · Post by **Harpoon** » 02 Aug 2011, 12:24

JBlackburn; am I able to get at this without removing the intake?

Post by **jblackburn** » 02 Aug 2011, 12:29

Yeah. Long needle nose pliers should help you with it.

It helps to have a girl's hands to help you (I have stupid big clumsy hands), or you can remove the radiator hose - which then makes everything a bit slippery.

Make sure you put a clamp on the hose or it'll just blow off again as soon as you put your foot in the gas pedal.

Harpoon · Post by **Harpoon** » 02 Aug 2011, 12:39

Thanks!