We just got a 2002 buick regal ls.we checked oil levels.good.the engine light came on after three days.what could be wrong.

trans problems,. check tranny ATF levels by the book and never done like and engine ever. "when he puts it in reverse it won't move like it is stuck in neutral yes engine always starts no stalls or stops thank you for responding"

REDUX 1 , tranny fails only and only in revere.
if the levels are good per the manual free below link
and the fluid is not NASTY, clear pink but can have light tan color not like mudd.
no metal shinny flacks see on end of dip stick.

the transmission reverse servo is bad, as most say so.

24mm

Was the oil changed?

make sure the air cleaner area is clean no debris the do the set up procedure

It can be the sending unit or the oil pump really has low pressure, have the oil pressure checked in the engine, if that is ok then the sender or the wiring to it is defective. DO NOT DRIVE THIS CAR UNTIL THIS IS CHECKED, YUOU WILL DESTROY THE ENGINE IF THE PRESSURE IS LOW. A NEW ENGINE IS ABOUT $3500.00, DO YOU WANT TO CHANCE THAT?

Your fuel sending unit is going out, Most of these are located on top of your fuel tank.beside your fuel pump. "You will have to drop tank to repair, good luck to you.

i'd say you have a ground problem if you are burning up alternators... sorry if that don't help... i would have to see car to better appreciate problem.

low engine oil level or the alternator not working or the alt. fan belt loose or broken...

check to see if a ground is off

that tell u that something is wrong, get a scan tool an pull the code.