2008 Silverado 4.8 Problem

[mattymax]

Buddies 2008 Silverado, 4.8ltr, 48,000 miles.

 

Cold engine he gets a "reduced engine power" message, happened three times over the past week. Also has a rough start when cold and doesnt want to shift out of 1st, also when cold. Engine light comes on and goes off speratically.

 

Read a lot of threads on the issue and some say same issue if the TPS, some clean and done, some replace.

 

Ran the check engine light, and he gets P0121; P2119 and P2135.

 

What do you guys recommend. Dealer ? ($100 just to diagnose)

 

Hes still under the 100K/5 year powertrain, but unknown if they will cover.

 

Thanks

-matt

[mattymax]

Anyone ?