My oil crankcase is filled with gasoline

[RickBlaine]

I am hoping for some suggestions please....my 1991 240sx Hatchback (103,000 miles) was idling poorly....so:

Installed NGK plugs and wires, cap and rotor, and a new valve cover gasket and spark plug gasket set. It still idled rough, but smoothed out on the highway. 0-60 mph times were slow- as the car had no life below 30 mph.

I checked the fuel injectors with an ohm meter. 2 of them were very bad, 2 were good. I ordered 4 matched rebuilt ones from Motor Man Fuel Injection of Michigan and installed them yesterday.

Could not start the car unless my foot was on the accelerator pedal all the way to the floor. Started the car, and grey smoke started pouring out of the exhaust system leak between the cat and the downpipe, and pretty much out the rear muffler and just "all over". Neighbors thought the car was on fire. It is not oil smoke, nor is it coolant smoke- it is unburnt gas smoke!

Pulled the oil dipstick and was SHOCKED to find it way above the full line, and it reeked of gasoline!

Before all this- it idled rough, but ran OK once on the highway. Now it only runs when smoke is pouring out and I am on the gas pedal. If I take my foot off of the gas pedal it dies- so I dare not drive it.

Is it my newly rebuilt fuel injectors? MAF sensor? O2 sensor? Clogged exhaust? ECU? An oil crankcase filled with way too much fluid (oil and gas)?

Any advice would be appreciated. Thanks.