engine/torque converter/tranny ?

It is a 1997 lunima 3.1, It starts fine engine runs good but when driving up asmall or large incline or hill it acts like the engine is missing if I hold the gas pedal steady. If I slowly push down on gas the tranny shift down to lower gear then runs fine. It will do it from anywhere between 35 to 75 mph. It has not trip a code because the light has not come on. Or does it record a code with out light coming on? Some people say that it is the torque converter or tranny solenoids or is it in the ignition system it has new wires and plugs. Took it to a couple mechanic’s they want $30.00 just to take it for a drive. Need some ideas

Exact same thing is going on with my 99 lumina. I hooked up a scan tool and commanded the TCC off, problem disappeared. A common problem with this transmission, it seems, judging by the amount of problems seen on the forum related to this. If you can find out which wire goes to the TCC you can unplug it and drive just fine, but you'll get lower mileage and probably wear out the tranny a bit faster.

It is only getting 25 mpg now a freind same year gets 28 all I know something is not right

Side note: The MIL will not always come on, usually only codes that are emissions-related will flip the MIL on.