2006 XC70 check engine light

[jimpierce7]

Engine system light came on today. Stopped by parts store to get the codes.
P0102 (MAF) and P0170 (fuel trim, running rich)
MAF is less than a year old but not Volvo. Auto Zone. Seems to be running fine but the gas mileage has gone down. At least on the dash it says it has.
Now, things got odd when I did my last oil change. I found a massive vacuum leak. I would guess anyway. The large vacuum line coming off the intake manifold was broken. The weirdness began after I replaced the broken line.

Any ideas where I should look? I'll get the check engine light turned off tomorrow to see if it stays off. I did clean the MAF and checked the air filter.

And she is running fine.

[earthworm]

Despite ''running fine'', there may more vacuum leaks … With a vehicle like ours , ten plus years old, all the rubber should be new/recent new … To test , spray the vacuum lines at their connections , where the cracks usually appear .
What is the age of your oxygen sensors .. these too should be recent/new .
Good luck

[jimpierce7]

oxygen sensor, down stream? is new. Odd thing, all is good now. lol Check engine light and all went out this morning. I am going to continue searching for vacuum leaks and maybe just replace all the lines.

[jimpierce7]

As I expected the lights came back on. I'm thinking it may be the MAF again. I had a problem it a year ago and replaced it with one from Auto zone........ after three failed attempts at O'reily's. Should this prove to be the issue again, yes I will get it from Volvo (FCP)

on another issue, is it just me or is the bottom bolt on the rear brakes a pain in the butt?

[abscate]

Aftermarket MAFS are known to give problems, but it isn’t usually the cause of trimcodes , either. Vacuum leaks are by far the more common problem.

[93SCMax]

As I expected the lights came back on. I'm thinking it may be the MAF again. I had a problem it a year ago and replaced it with one from Auto zone........ after three failed attempts at O'reily's. Should this prove to be the issue again, yes I will get it from Volvo (FCP)

on another issue, is it just me or is the bottom bolt on the rear brakes a pain in the butt?

The Volvo brand is from Bosch. You can get a junkyard one pretty cheap. If you go this route, double check the PN against your current MAF.

When I first read your post, I assumed your engine light was due to a non-OEM MAF. There are lots of previous posts concerning this issue. I believe the general concensus is only use an OEM MAF.

Good luck.

[Georgeandkira]

Start shopping around for code reader of your own.

The ability to read and clear multiple codes at once THEN being able time check any particular code's recurrence is extremely helpful.

It's great if your local shop has a good one but their's is likely quite basic if not cheap.
For a few dollars more you can buy one with a basic library of causes and maybe even repair suggestions.

[jimpierce7]

Thanks folks!! The search is on!!