I have a P0303 cylinder 3 misfire. I suspect it's carbon on the #3 cylinder intake valves which I have to clean off. What is the numbering of the cylinders? Is it #4 on the car's own left side (US driver side) and go from left to right: cylinder 4, 3, 2, 1?

 

1 is on the passenger side - 4 is driver side

Firing order is 1 3 4 2 - different from physical order

 

After considerable research, I've determined that the cylinder numbers are
1, 2, 3, and 4, a.k.a. one, two, three, and four, but not I, II, III, or IV (nor even IIII as some watch or clock dials have,
or at least they did before everything went digital).

 

 

Now there's a smart ***.
Good thing Red Forman isn't on this forum or I'd get called something else.