97 Blazer w/ 127,000 miles. RPM's start bouncing between 1500 and 2200 at about 50 MPH.
Been doing this about a week, check engine light popped on and OBD11 code reads 1782 with Powertrain lighton. That code is not in my manual? What could this be? How can I fix?

 

Doesn't show up as a valid code in any of my references that I have access to at work either... I will have to check my AllData disks when I get home.

 

Kyle: I think that I discovered what the OBD11 code is trying to tell me; it is GM code for "Check your tranny oil level, (can I say STUPID!)" on this site??LOL at myself!! I checked cold level only, several times, but did not check hot. Now I know what the transmission does, it sucks up the fluid when it is running, and drops back to the pan when it is cold. So where did the oil go? I crawled under this A.M. and discovered a loose bolt on the pan was leaking probably a long time. No drips on garage floor, or where I park at work every day. Filled to proper level, (while hot!) and running smooth again. Do they call the check engine light an "idiot light"? Wow, lesson learned. That's why the manual says check both hot and cold. Maybe someone can learn from my mistake, or at least get a good laugh.