1986 Chevy Celebrity electrical problem

I have a 1986 Chevy Celebrity 4 cyl and here a wile back when driving for maybe an hour or more the car would lose power I would have to down shift manually and release gas peddle for about 5 to 10 seconds while going down the road. After the 5 to 10 seconds I would regain power to the vehicle. The problem progressed until it finally quit working. Parked the car, replaced distributor, spark plug timing module, spark plug wires, coil pack, spark plugs, fuel pump, fuel filter, and computer. Timing on the vehicle is still good, however it tries to start but will not start up but is getting fuel and spark. After replacing all of these parts when trying to turn vehicle over and pump is engaged, the fuel gauge goes WAY past full, also when pressing the break with car on or off it does the same thing along with trying to turn the lights on. When vehicle checked for codes, it pulls code #42. Is there any possible way that you may know what is going on with my car? Its costing me a lot of money I don�t have at the moment.