I drove my blazer to work and it was fine on the way home it would not shift into 3rd or 4th gear. I crawled under and there is a small amount of fluid around the transfer case and axle. At the same time my check engine light came on which was probably a result of the high rpms. the code i pulled was maf or vaf circuit low input. Does anyone out there no if there is anything that could be causing my shift issue on my 98 4x4 chevy blazer 4.3L.