Chevrolet Repair: Tahoe Trans Electric?, hazard switch, valve body

Question
I have a 1999 Tahoe.  I have had it in the shop for 3 weeks with the mech trying to diagnose it.  It runs a shifts fine as long as you don't floor it.  If you are in say 3rd and floor it so it will downshift, it will slip until you let up on the gas. After it goes into gear, then you can floor it again and it wont slip.  Also sometimes when cold if you do the same thing, it will buck in and out of the downshift.  It throws no error codes?  Every part in the trans has now been replaced including the case and valve body.  My mech can't figure it out (he is fully trustworthy...been doing stuff for us for years).  Interestingly, the original repair was for the hazard switch shorting out and not letting the brake lights work.  After that whole turn sig assembly was replaced for the hazard switch (don't get me started) I noticed this. At first I didn't think much about it.  Could this be related.  Mech says the pressures are good, although he thinks they could be higher. If it was electrical wouldn't it have an error code? I have the 5.7 engine.

Answer
Hello John, I don't think it's electrical. Yes it should have codes if it was. I can't drive this truck so I'm not sure on what your feeling with the trans. Please do this..Replace the FUEL FILTER !! I know it doesn't sound right but this filter can cause a lot of problems. Yes It will make the trans feel like it's slipping too.

Let me know what happens

Have a Great Day     Mark