kick down, 5k rpm, no acceleration

[dicksx5]

Hello all. Here's the senario. Going about 40 MPH. kick down (past click) engine throttles up to 5k rpm, but no acceleration, just sits there. However if if use S mode, car will take off no problem. I have codes showing up Lean bank 1 and 2 (P0171/74) recently changes crankcase hoses, just wondering if this is releated. thanks

[Big "J"]

P0171/74 are usually caused by bad gas or O2 sensor going bad (precat). I don't think CVV hoses have anything to do with the tranny not engaging in K/D. Do you know if your tranny had the software update that's been posted before? Check into that and if so, check your tranny fluid level?

[dicksx5]

ok apolgies, 01 4.4 with 130K on it. is the tranny software fix applicable to this or was it 04's and on?. Not had any tranny lights coming on, so was wondering if linked to vacuum leak?....

[Big "J"]

Well, if it works fine in sport mode.... then I would think normal mode would be the same. That's why I don't think your CVV would apply. Sport mode just has you shifting at higher RPM's. The higher the RPM's the more pumping the tranny is doing and probably why sport mode works fine. Although, I wouldn't rule out a vacuum leak to cause various issues and could possibly cause your P0171/74.
How long have you had it? Have you changed the tranny fluid prior to this? With 130K changing the fluid now is kind of risky.

[dicksx5]

had the car for a year, drives great, would not know there is a problem unless you kick down past the click....then nothing. you recommend tranny fluid change or not?

[Big "J"]

Changing the fluid may help or make it worse being you have 130K on it. It's a tough call. Some folks here say leave it alone and nurse it until it totally dumps on you and others recommend changing it.
If it were mine and it only acts up when going to K/D and the rest of the time it's fine then I'd leave it alone and wait and try not to use K/D.