I have a 94 Pontiac Bonneville. The check engine light goes on sometimes. At idle, the oil pressure oscillates up and down. The check engine light usually goes on after going high speed and slowing down to a stop.
I have tried to find a code reader for it. The connector is trapezoid (D-shaped). This is supposed to mean that the computer is OBD II, but since the car is a 94, it was during a hybrid year and needs a OBD I to OBD II adapter.
Can anyone tell me a way to read the codes?
Jon