First gear is reving high before shifting. This is the only shifting that is a problem, thought it may be the transmission, but after having a reputable shop check it, they said it is MAF sensor, or a leak. Changed the air filter, and looked at MAF, and it looked clean. But, problem still persists. Suggestions please.
Check for hoses off or holes in them anywhere on engine. Check the duct work to make sure it is all connected from maf to throttle body, check for a vacuum leak if this is a big block-8.1L check to see if intake bolts are tight they shold be 44 inch lbs or 5 Nm