No power on hills will not make it in over drive no matter how fast I'm going before the hill.

Already did a tune up and change. Tension pully what else could it be.

Started out not shifting from first unless i let off the gas
And now wont shift at all its automatic transmission fluid looks good and smells good. And parking brake light wont go off

It's a v6

It's almost exactly what Visitor reported. Someone commented he thinks it's due to the anti-theft alarm system. I also believe the same. Can I remove or disable it safely. If anyone can help, I'd appreciate it very much.

Sometimes it gets to much gas (black smoke out of tail pipe) and sometimes no gas at all. A couple small broken pieces feel out of the steering column.I have changed all the senors and relays in and around the engine. Changed ignition control module, fuel filter,computer, electronic fuel injectors,exhaust system,checked wire harness 3 times for breaks, etc.

I was just wondering witch manifold I should buy to upgrade from stock and by doing this will it increase horsepower/torque?