Having problem going in and out of 3rd GEAR!! PLZ HELP!!!!

[SparkZDMAX14]

ok, so I have a 2003 2500HD Durmax diesel crew cab automatic transmission and the truck has 68,000 miles on it, it has the Banks catback exhaust and the Banks SIX GUN chip, when I turn the chip to level 6, and take off it seems like it never wants to get out of 3rd gear, it stays at 3,000 to 3,500 rpm and never gains any speed, it stays at 45mph, it does that for awhile and then eventually shifts, wats wrong? PLZ HELP

[More Power]

It sounds as though level 6 is putting the transmission in limp mode....

Are you getting any codes?

Jim

[SparkZDMAX14]

no codes, but yesterday I drove it to see if it did it on any other level and it does it threw levels 2 to 6, it seems like it doesnt weant to get out of third, and it doesnt give any codes

[DmaxMaverick]

Could be the tranny "learn" process. Many times, shifting issues come up when changing power levels frequently. The TCM gets confused, and shift hangs are common.