2003 Vauxhall Astra intermitting piston 2 misfire

Checked coil pack means that work ok?

Spark plugs Ok and correct?
Compression?
Crankshaft sensor failure? (Most common/reprogram the ECU )

Give me your chassis number and engine number so I will add the fault to TECH2 for suggestions

According to P0302:

Cylinder 2 Misfire Detected
Too many misfires detected by the crankshaft position sensor

Check hose connectors and fittings on intake system / vacuum system

Check all vacuum lines of the following component for tightness and proper installation:

Check air filter for fouling and correct mounting.
Intake hose
Throttle-housing
Check function of the tank ventilation.
B21 Sensor - Absolute Pressure, Intake Manifold
Brake Booster
Y4 Solenoid Valve - Exhaust Gas Recirculation
Check the following component for tightness and proper installation:

Oil Dipstick
Oil Filler Cap

Check the following component for tightness and proper installation:

Y4 Solenoid Valve - Exhaust Gas Recirculation
exhaust manifold
B117 Sensor - Oxygen, Mixture Control, Heated
B118 Sensor - Oxygen, Catalytic Converter Check
Exhaust system
Catalytic Converter
(leakage, blockage)

Check fuel reserve
Check fuel tank for correct fuel sort content
Note:

The fuel reserve must be greater than 5 L

Check the following functional group for proper operation:
Spark plugs
Perform a visual check of the following components:
Catalytic Converter

Defective component:
T1 Ignition Coil - Direct Ignition

Note:

Check catalyst for mechanical damage by tapping against the shroud. Perform visual check of catalyst shroud for thermal overheating (red-violet discoloration).

Injectors are cleaned and you saw it after?
Not correct fuel rate or water in the tank?

While its idling, give the EGR valve a good tap. It may not be seating well and will cause low RPM misfires.

Common Problems That Trigger the P0302

Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable)
Incorrect ignition timing
Vacuum leak(s)
Low or weak fuel pressure
Improperly functioning EGR system
Defective Mass Air Flow Sensor
Defective Crankshaft and/or Camshaft Sensor
Defective Throttle Position Sensor
Mechanical engine problems (i.E."”Low compression, leaking head gasket(s), or valve problems
Common Misdiagnoses

Fuel Injectors
Oxygen Sensor(s)
Power Train/Drive Train problems
Polluting Gases Expelled

HCs (Hydrocarbons): Unburned droplets of raw fuel that smell, affect breathing, and contribute to smog
CO (Carbon Monoxide): Partially burned fuel that is an odorless and deadly poisonous gas
NOX (Oxides of Nitrogen): One of the two ingredients that, when exposed to sunlight, cause smog

Hmmm looks catalyst as you say about the light. Do not forget that their life is at about 60K (a nd their cost not so economy)