Someone told me that the EGR valve maybe coked up on my Baja which is why it wants to buck a times at cruise. Supposedly the valve cannot make up it's mind whether it's open or shut due to the carbon buildup.

 

Years ago I had a 96 Ford Explorer. The check engine light came on because the sensor that detects whether the valve is open or closed was showing open. There must have been just enough carbon between the valve and the seat to make the sensor think it was open.

 

I connected a vacuum hose to it, sucked on it open the valve and threw it in a bead blast cabinet and cleaned it up. I reset the computer and all was fine.

 

But there is no vacuum hose going to the EGR valve on my Subaru. Instead looks like a connector with 6 pins.

 

How can I open the valve to properly clean it (if that's the case).

 

I still don't see how running 89 octane is making this car run smoother. Unless the higher octane is masking some other issue. Or it's just a coincidence.

 

This weekend I'm going to get some of that MAP cleaner, pull the air box off and give it, the sensor that is mounted in the air cleaner box (air temperature sensor) and the throttle body a good cleaning. I wonder if the oil from my K&N filter has something to do with this. And install a paper filter. Seems like the problem cropped up after installing the K&N filter.

 

 

 

 

 

Not your K&N , I run them on both my obw's with no ill effects.

Our '05 2.5 forester has had the EGR valve stick open, shows up as a won't-idle issue. Stuck shut- maybe the timing would be cut back excessively to stop the pinging?

jseabolt,

 

I'd try oven cleaner sprayed into the cast openings of the valve. You might even try immersing just the cast section entirely in oven cleaner overnight. I don't think that getting the cleaner on the plastic bits would be wise.

 

After rinsing I'd then be tempted to burn any remaining coked material with a fine flame from a propane torch. Then spray some 4D40 onto its valve parts and exercise the valve control rod up and down with needle nosed pliers.

 

If that doesn't free the mechanism up, then its time for a new one. Good Luck!