OK, I replaced the PCV system in my 850 glt, because it was having idling issues and was smoking a bit. Anyway, I got it done, but it still idles a bit rough at traffic lights. Checked the codes and it only gave me 121 (MAF sensor). Before I redid the PCV system I also would get 443 (cat efficiency low), and codes for O2/ too lean/rich and misfire.
Looking at MAF sensors for sale, the sellers needed the number on the housing. They show numbers like "0280217107" but the code on my MAF reads: "107 MM112DCA9108." And there is a sticker with another number but most of the digits have worn away. How would I get a correct match?
(Yes, I cleaned it with MAF sensor cleaner.)

Also, would you need a special tool to remove the fuel filter, or can the connectors pop/snap off?

 

l dont think a bad maf would cause a rough idling. a vacuum leak will be the likely cause of your rough idling.how clean is your throttle body? it will be a good idea to check your idling control valve if its clogged.
Google Image Result for http://c.fixya.net/fixya20/uploads/Images/EF05B60.jpg

 

I cleaned the throttle body well when I had the intake manifold off. I made sure I had refitted all the vacuum lines, and replaced a couple. I cleaned out the idle control motor and replaced both hoses on it because they were brittle.

 

no tool is needed to remove the fuel filter. the connectors will come off

 

Fuel filter how to with photos:

http://www.matthewsvolvosite.com/for...hp?f=1&t=31420

Looking at MAF sensors for sale, the sellers needed the number on the housing. They show numbers like "0280217107" but the code on my MAF reads: "107 MM112DCA9108." And there is a sticker with another number but most of the digits have worn away. How would I get a correct match?

Who are the sellers you're looking at ??

 

l wondered that too. if you are trying to get a MAF you should go OEM which is bosch

 

Thanks, that writeup is helpful.
I'm looking at various ebay sellers... any of them I should avoid?
FCP has it for $164.89, and that is the Bosch.

 

FCP is a reputable seller. l always avoid ebay. l dont trust it

 

check partsgeek.com they have good prices too

 

I don't think you've said what year it is but I'd look it up online at IPD, FCP, oreilly, autozone or NAPA and check what part numbers they list for your year, make, model, engine, turbo/NA, auto/manual. Check at least two and make sure you come up with the same part #. Once you have a number shopping on ebay might be easier.
Most of them also have part interchanges and that might work for you too

Are you looking for new(reman) or used?
What was the Bosch P/N you came up with ??

 

It's a '95 GLT, automatic, N/A.
I know the good rep of FCP; I ordered the PCV kit from them along with the replacement hoses for the idle control. All except for the flame trap were genuine Volvo.

The number on the housing of my Bosch MAF:
107
MM102DCA9108
The number of the Bosch sold by FCP is 0280217107.

If the idle control motor failed, would it put up a code?

 

yea l think so, am not hundred percent sure but you would get a rough idle with a bad IAC

 

Yes it would.

 

I guess I may have to get another IAC; as I wrote in the OP, I replaced both hoses on it because they were brittle and cracking.
The fuel filter replacement was indeed simple... the only hassle was lining up the holes in the bracket for the bolt.

I'm still only getting the 121 code.

 

Update: I got a new MAF sensor (less than $30 from an eBay vendor) and it took care of the idling issue. Also, no CEL so far. I don't think I needed the IAC.
Only issue: I get a smell in the cabin when I stop and idle at a light; similar to exhaust, but no smoke. I'll be looking in the engine bay for any places where fumes can seep in.

Had a garage replace the timing belt, because it was last changed nine years ago. The mechanic, a Volvo specialist, only charged me $450, $100 less than his estimate because the tensioner was still good. (Another Volvo-specific garage in town wanted $800 because they wanted to replace the seal as well as the timing belt, pulleys and tensioner. No mention of the water pump.)

 

what else did the mechanic change besides the timing belt?

 

Hopefully you had the water pump replaced. Reason being, if it breaks it will take the belt and likely a valve or two, possibly the head with it. I believe in doing it every belt but others will say every other or every three. I guess it depends on how lucky you feel.

 

Well, the car survived a 450-mile trip to south Florida and a return trip two days later. Only bothersome issue is the oil/exhaust smell getting into the cabin at idle especially when the AC/heat/fan is on. I made sure the cowl was sealed tightly when I installed a cabin air filter. I looked at the engine when it was running and there appears to be smoke coming from the area of the EGR valve (I had to remove it to take the intake manifold off: I had rebolted it with gaskets included after I reattached the manifold). I'm assuming there could be a leak at the valve.

Update: I replaced the vacuum tree (which I should have done the same time as the PCV system), and noticed that one of the small inlets was clogged. I sprayed out the opening on the manifold with throttle body cleaner and cleared out the hole that leads to the EGR valve with a bit of wire before I installed the new tree.