Gas Guage worked fine and was always accurate until I changed the fuel pump out and now it isn't working at all

my gears is shifting.

rear access window keeps popping up every time i take off the alarm or i open the back door

And it say reduce engine power what does this means

The headlights won't go off and it just started this morning.

Occurs almost daily. Have replaced rear & front shocks & struts replaced shock absorbers & all ball joints and control arm, stabilizer bar, in March 2015. Also replaced Susp Air Compressor not sure what that is (A/C?)also have new tires & oil pump.

Had it serviced, stil goes off. What say u?

Shop turns off light, but it comes back on a day or two later. Previously the gas tank vent was plugged and the chamber containing the air filter had leaves and water in the bottom. Said problem was solved. Not.

I replace the gas cap but the light still keeps going on and off