Under the vehicle, passenger side, 2 feet in front of the rear tire, just inside the frame.
Which solenoid? BOB
Bottom of engine, inside the oil pan.
gmac05062023a
Solenoid
Remove the grill
Oxygen SensorOxygen Sensor Location
Not without serious modification, but anything is possible if you have enough money for a conversion.
Remove the fuel tank to gain access to it.
I have used regular "87" octane gas in my 1993 Buick Roadmaster for 7 years and it runs like a top. I don't know the gas mileage as my odometer doesn't work, but it seems to be OK.
flush the heater core in both directions with water
Remove the crossmember and drop it out the bottom no problem.
Bottom of engine, passenger side, next to CV joint.