Year, make, model and engine size would help, but a bad spark plug, spark plug wire or fuel injector are a few possibilities.
No
this sounds like a missfire. check your spark plug cables make sure they are in place nice and thight.and the correct place (order).
If the cat was damaged and restricting the exhaust it could cause a random misfire (P0300) but you would also have a severe loss of power.
Many manufactures make a 2.2 engine. What make are you asking about?
you either have bad piston rings or your valves are staying open. Other Possibilities: Blown head gasket; cracked cylinder head; cracked piston.
make sure that the number 1 piston is at tdc on the compression stroke, then look and make sure the rotor is pointing at number 1. if not lift the distributor up and turn it towards the number 1 cylinder and put the number 1 wire on the cap were number 1 is, then wire it 1,8,4,3,6,5,7,2 clockwise It probably means that the piston is between the exhaust and intake cycle and that you need to turn the crankcase 360 degrees. That should put the distributor in the right place.
The piston rings are fitted round the piston to make a better gas-tight fit in the cylinder.
Gently, they break easily. They also make tools to R&R piston rings to avoid breaking the rings.
The purpose of a piston ring expander is to make it easier remove and install piston rings. Because of the low torque they use, they help to prevent damage to the piston rings.
you cant
It will make it imossible to start. 2-strokes depends on a tight seal between over- and underside of the piston. A cracked piston will also disintegrate on high revs.
You need to turn (screw, rotate) the piston clockwise in the caliper a large number of times to make it fully retract. You can insert some kind of tool into the indentations in the face of the piston, or grip the very top edge of the piston with pliers in order to turn it. It has to be fully retracted to allow enough space for "new" pads to be installed.