2008 XC90 3.2L with codes P0171 and P0174 - Help

Hey guys,

I have a 2008 XC90 3.2 AWD with 75,000 KMS that I got recently.

Checking with OBD FUSION, I got the codes:

P0171 and P0174 System Too Lean

P0507 Idle Air Control RPM Higher than expected.

The car feels and drives normal but I want to fix these before it gets worse.

Searching on the web for these codes P0171 and P0174 its look like maybe the problem is the PCV but I don’t find any info, pics or DIY fix for this issue on a 3.2L engine

Have any of you with 3.2L engine has experienced these same codes?

I going to check if I have a vacuum hose leak but can you advise were I need specially to look

Thank you for your time and help

Isaac

http://i85.photobucket.com/albums/k5...psandckmc5.png

I had P0172 system too rich but this was on an 850 - it was the vacuum hose elbow to the left of the inlet manifold (not sure if similar exists on your car), all rubber elbows definitely worth a check!

Looked like this:

http://i1257.photobucket.com/albums/...psusbunard.jpg

Is your lambda light on?

Sounds like an air leak to me. Check all your vacuum & breather hoses. If you can get yourself to a garage with a smoke generator and pump smoke to find the leak.

Hey Guys.

After several web search, I found that these two codes are related to the PCV OIL TRAP – VALVE COVER. Since the membrane/diaphragm is damage, it alow air to enter in the system that the MAF is not metering and that why it trow System Too Lean codes.

This is causing a small misfire and I am pretty sure is consuming more fuel.

So today I was checking the black housing on top of cylinder head and the first thing I notice is that is all covered in oil.

Also notice a hissing noise that is coming from the engine oil cap. I removed the oil cap and put my hand over the hole and there is a "noticeable" suction.

I am thinking in ordering:

PCV OIL TRAP – VALVE COVER Part No. 31319642
VALVE COVER GASKET Part No. 30731243

Can you guys, let me know what’s the correct torque setting for the torx screws for the PCV OIL TRAP VALVE COVER?

Thx for your time and help

Isaac

http://i85.photobucket.com/albums/k5...psfnax4kxy.jpg

Hey Guys,

So today I have more time to check the valve cover Oil Trap and in the name of the science, research and investigation :-) I decide to remove the plastic cap on top of the diaphragm housing.

I know other brands like VW and BMW sell the membrane/diaphragm alone so I was expecting to see if I can replace it and save some $$$

I went to a place where they sell OEM and aftermarket parts for BMW. They were very similar but none of them fit or was the same.

On the Volvo membrane/diaphragm there is a part No. CF W 3A MB66-24
Doing a search on the net I don’t find anything under that part No. or something similar.

Anybody knows where can I get this part? If not, I will have to buy the complete valve cover oil trap :-(

THX,

Isaac

http://i85.photobucket.com/albums/k5...psmrvocjct.jpg
http://i85.photobucket.com/albums/k5...pspzguj12v.jpg
http://i85.photobucket.com/albums/k5...ps2dpa1uzs.jpg
http://i85.photobucket.com/albums/k5...psrcfknlqe.jpg
http://i85.photobucket.com/albums/k5...psjxstwgsc.jpg
http://i85.photobucket.com/albums/k5...psj6begbbg.jpg
http://i85.photobucket.com/albums/k5...psvvrf9nol.jpg

Hey Guys.

So yesterday, I change the PCV OIL TRAP – VALVE COVER Part No. 31319642 on my 3.2L and cleared/reset the P0171 and P0174 System Too Lean codes and now the engine is smooth and not misfires.

So today I was driving and my check engine light come on and these are the codes I get:
P0172 and P0175 System too Rich.

Any advice what to check? Or what other test to make with the OBD Scanner?

THX,

Isaac

Here is the screen shot of the OBD Codes and also the Term Fuel % on idle on Bank 1 & 2

http://i85.photobucket.com/albums/k5...pshhjudhax.png

http://i85.photobucket.com/albums/k5...pscgcyu5cv.png

Hello over there

I've not familiar with this engine but a bit of searching on the net showed these codes might be caused by oxygen sensor, MAF or vacuum leak

Can you get access to a better diagnostic system? It would be expensive to replace the above mentioned components without knowing 100% they are defective.

Vacuum leak can be found by smoke testing.

http://www.justanswer.com/volvo/7x27...ow-sensor.html

//edit

just noticed two guys above have already suggested air leaks :B_thumb: