What would cause a Chevy truck to lose power going up hill?

Answer 1

OK There really is not enough information in your question to give you a good answer but I'll try to give you some ideas. First is the transmission downshifting going up the hill? Is there a rotten egg smell when you lose power? If there is you have a bad catalytic converter. How long since the vehicle was tuned up? Older trucks require it more often than newer trucks but nothing runs forever without proper maintenance. Lastly understand that all engines seem to lose power going uphill because they are working harder. Unless some action is taken such as downshifting you will continue to bleed off speed and therefore RPM and lose power. Also, check your oil level, and Transmission Fluid level.