'07 Audi A4 2.0T won't start

Hi all,

Audi A4 will crank, but not start, AT ALL.

I changed the oil, and the oil filter in my Audi A4. I replaced the filter with a
new one, and poured 5w-30 instead of 5w-40 like the recommended. The
owner's manual said that 5w-40 is recommended but 5w-30 will do just fine
as well.

How it happened: I was driving, and I got a RED Oil pressure warning light.
I stopped at the side of the road, checked the dipstick, oil levels were fine.
They were at the max, and the oil was not leaking all over the ground, or
anywhere else.

I turned on the car again, drove for about 15 miles without the oil pressure
light, put it in sport mode, pressed hard no the gas pedal after the light
turned green, and I guess I was at 6K/7K RPM and then the oil pressure
light came on again. I was 2 minutes from home so I just drove home.

The next day, I take it out for a spin again, and the oil pressure light is on
without doing any sport mode shifts, or high revs, etc. I drove for about a
total of 3-4 miles until my car shut off.

I was stopping at a red light, and once I was completely stopped, my car
turned off completely. The Check engine light came on, and so did the EPC
light.  

Cranked 3-4 times, car started again, got to the next light, it shut off once
again. After I cranked it once again, and it started, I got to the nearest
parking lot, and then the car shut off completely and would not start again. I
kind of heard the engine sputter out a little bit, as if it was kind of like a
diesel engine.

I've checked the:
Timing Belt
Alternator/Alternator Belt
Distributor
Spark Plugs
Fuel Injection
Battery

All seem to be working fine and trying to do what they are supposed to,
timing belt tries to move when I crank, etc. Alternator belt tries to move
when I crank. And of course if I crank it long enough, the belts do indeed
keep trying to spin, the car just wont start.

Also, the huge pan that is on screws under the Audi was taken off and I
never put it back on again. I took it off to get to the oil filter, etc.

I bought a cheap VAG-COM cable on Amazon the other day and it should
be here tomorrow, and I will try to test. What a great way for my car to tell
my happy birthday...