It's funny...for all the times I hear and read people saying injectors..it's typically something else. Injectors maybe 1% of the time.

Let's see.. maf and tps have a lot to do with trans shifting. Only real difference between 4T60 and 4T65 shifting is the pcs vs vacuum controlled. This effects the shift pressure, not timing or gear. So we can rule that out.

Say his tps or maf are off or screwin up. That could do it.