Please Help! Error code and repair question.

[ranger89]

Please help!

I own a 1989 Ford Ranger with the 2.3L 4cyl eng. The truck is in great shape and only has 40,000 miles on it. I got it for a good deal because it sat for 6-10 years with little or no use.
I have the truck running and running great with one exception. When I put into (P)ark the engine stops running, like it is getting no fuel or air. The transmission seems to shift fine the only noticeable thing is shifting from one gear to another while stop causes the truck to lurch slightly. I took it to the dealer ship and put it on the diagnostic machine and it came up with an error code of 66 (MAF/VAF Low, Bad MAF/VAF) I have since changed the Mass Air Flow sensor and MAP Sensor. These changes have not made any differences in the way the truck runs. I am running out of ideas. Any help would be greatly appreciated!

Thanks! Ranger89