[andy_06xi]

I noticed early in the week a stumbling idle when cold. Driving under load seemed OK and the idle smoothed out as the car warmed up. On Thurs, the 'Service Engine Soon' light went on.

I viewed this as a good thing -- as it mean that a code was probably stored. I scanned the DME using my Foxwell scanner and got a MAF error (2D06).

I thought it might just be a poor electrical connection, so I pulled the connector and sprayed both the connector and sensor end with contact cleaner. I actually have a replacement socket lying around -- but I didn't want to fool with pin removal just yet. I didn't feel any looseness in the connection. Anyway, I then drove the car around the block. Same stumbling idle and the 2D06 code came back.

I then pulled the MAF sensor itself and sprayed it with MAF cleaner. This also gave me a better angle to use contact cleaner on the sensor pins. I put the MAF sensor back in and hooked it up. The drive around the block was smooth and the code didn't come back.

I've since been driving it for the past day with no symptoms and no codes. Fingers crossed! Otherwise Rock Auto has a good price on a VDO branded replacement (this is the same brand that came with the car -- which currently has 186K miles).

[andy_06xi]

Unfortunately the symptoms came back as well as the MAF code -- but in a frustratingly intermittent fashion.

I tried replacing the MAF as well as cleaning the electrical contacts.
I replaced the red, rubber gasket on the electrical connector.
I tightened the air intake hoses.

Still symptoms would come back (just on cold idle) and throw a code.

I finally broke down and took it to my Indy -- who suspected a vacuum leak and smoke tested under the hood. He found the oil filter cap gasket was not making a tight seal (though I had cleaned it as one of the things I tried) and he replaced the cap.

So far (after 4 days of driving) so good. No more rough idle. No more codes.