Joe Romas wrote:
rtmil46.
I notice in your Signature you've got B20. Do you make a steady diet of it? Just thinking the reduced soot should have helped your EGR valve. Or maybe it prolonged it

On the excess oil in the intake plumbing, does your pro-vent catch most of it?
Oops, sorry. It was your MAF sensor that went out

Nope, you were right. At first it was just the MAF sensor code, but within 100 miles it was also throwing two additional codes for the EGR valve. I'm thinking it IS actually the EGR valve in this case, not the air flow control valve, primarily because it it threw the MAF sensor code first, then the two EGR codes (ie, a gradual failure), it still was getting decent fuel mileage, only noticeable signs were a lot of black smoke on any throttle change and quite a lot of delay on the throttle on accel and a lot of throttle required on hills. Prior to taking it to the original dealer and finding the other two codes, I checked out the AFC valve and my intercooler hoses. AFC valve was clean and still working, hoses were still nice and clean with no oil. This was after it threw the CEL for the MAF sensor. IMHO, the MAF sensor is fine, it's the EGR valve causing the codes from the imbalance in air flow.
Other than the first 800 miles, and a 3K mile trip to TX (11900 miles total) I've made a steady diet of B20, with the idea of reduced soot in mind. I'd tend to think it did prolong it's life, along with the Provent and keeping the oil out of the intake. 20% reduction in sulfur ain't much, but it's better than the other crap we have for fuel locally. Given the gradual way in which it failed, and the gradual effect on driveability, I'd have to say that, yes, running B20 and a Provent did help.
From what I've seen of the Provent, for the first 2 or 3K miles until the filter element gets loaded up with oil, you'll still have some oil mist making it's way thru, based on checking the outlet hose. But for the last 5K miles on mine, the outlet hose has been bone dry. I tried wiping out my intercooler outlet hose and the intercooler stub tubes with a rag soaked with starting fluid before taking it in for the EGR replacement, I didn't get ANY oil residue on the rag, at least 5K miles since the last time I checked them.