my Skoda Octavia NFL (2020-Present) has a rough idle when cold what should I check

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Replace Air Filter

• Locate the air filter housing and open it.
• Remove the old air filter and inspect it for dirt and blockages.
• Install a new air filter (ensure it meets OEM specifications).
• Reassemble the air filter housing securely.

3. Check and Replace Spark Plugs

• Remove the engine cover if necessary.
• Disconnect the ignition coils, then remove them using a socket set.
• Remove the old spark plugs using a spark plug socket.
• Inspect the spark plugs for wear; replace if necessary with OEM spec plugs.
• Gap the new spark plugs according to manufacturer specifications before installation.
• Reinstall the ignition coils and engine cover.

4. Examine and Test Fuel System

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position without starting the engine to check fuel pressure.
• If pressure is low, inspect the fuel pump and fuel filter for blockages or malfunctions.
• Replace any faulty components as needed.

5. Test and Replace Coolant Temperature Sensor

• Locate the coolant temperature sensor; disconnect the wiring harness.
• Use a multimeter to check the resistance of the sensor; compare readings to specifications.
• Replace the coolant temperature sensor if it does not meet specifications.
• Reconnect the wiring harness after installation.

6. Clean or Replace Idle Air Control Valve (IAC)

• Locate the IAC valve and disconnect the electrical connector.
• Remove the IAC valve from its mounting position.
• Clean the valve with a suitable cleaner; if heavily carboned, replace it with a new one.
• Reinstall the cleaned or new IAC valve and reconnect the electrical connector.