All,

This morning on my way into work, the CEL came on in my 2008 Subaru Outback 2.5i with 170k miles on it.  The code reader showed P0026 and P0028, I've read that this can be caused by dirty oil, low oil, PCV Valve, VVT Solenoids, and finally oil pressure sending units.  

Have any of you guys ever experienced this, know of any simple testing to easily diagnose which is the likely culprit?  i.e. multimeter on solenoids and sending units  Obviously changing oil seems like the simplest option (got about 1k till the normal change interval).  

Thanks in advance,
Zach

I've seen those codes before, on different makes. Start with changing the oil, and use a Subaru filter while you're in there. Make sure you're using the right weight oil, and don't buy synthetic, in case you have to drain it back out.

Clear the codes if you can, and see if they come back. If they do, you're gonna have to tear it down, and replace the VVT pulleys.

I would suspect the PCV valve at 170k if it's never been done before.
Not sure on the Subaru but other makes I've messed with before was just a simple and shake it to see if you hear the check ball moving. Should be cheap and easy to replace too.

I just looked these two codes up on AllData. Looks like a bunch of other techs (28) have had good luck replacing the INTAKE VALVE CONTROL SOLENOID. Seems like a simple job, one bank pays .6 the other pays .8 of an hour. The trouble tree for diagnosis says the same thing. Unless you had a rat chew through your harness, it's most likely those two solenoids.