Any ideas on what to check on a 98 V70 with trouble code #P0172. The seems to run well but i would like to repair it.It has 93,000 miles and new rotor, cap, plugs and wires less than 10,000 miles ago

I had the same code on my 98 V70 GLT just before I took a trip to FL this month. There is a vacuum hose with an elbow that attaches to a nipple on the right side of the intake manifold. Check to see if that elbow is deteriorated as mine was. It's a tight fit in there but if the elbow is deteriorated, replace it and reset the CE light. It can be done without removing the intake manifold.

I did so and the code has not shown up again.

i found that i do have a bad vacuum line under the intake manifold. Did you use an volvo part or just a piece of vacuum line? it appears that the other end attaches to a larger rubber line, does it fit inside or is there a nipple? Did you remove the power steering resivor or the thermostat and cooling hose? thanks bobd

I used a genuine Volvo part that I purchased from Tasca Volvo in Seekonk MA via mail order. Bought three of them very cheap. IPD also ha$ them. Didn't remove anything. Fortunately, with a couple pairs of angled needle nose pliers and my wife's small hands, I (She) was able to put the new one on the vacuum hose and the flared end on the intake manifold nipple. It can be done, but with difficulty...good luck

I replaced the line yesterday. I wound up removing the top radiator hose to fit my big meathook hands in but it went well. I reset the lite and so far no trouble. I am hoping that my fuel milage will go up since the hose was in such bad condition, it looks like it could have been collapsed for quite a while before it opened a hole the rubber was badly deteriorated. Does anyone know where the line leads to and what part of the system it is for? Thanks all

Believe it leads to the oil separator/trap under the intake. If you're nearing 100K miles, my thoughts are that the entire PCV system which includes that trap and other small vacuum hoses will need replacing fairly soon. I did mine in Dec. and it was a bit of a chore. I had to take the intake manifold loose.
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1998 S70 T5 Emarald Green Metallic, 2004 V70 2.5T Ruby Red, Previous Owner of Black '94 850 Turbo Wagon. My cars have been running so well lately they've got me worried.