why does my Jaguar XF X260 (2015-2024) lose acceleration on the highway

Symptoms

• Loss of power during acceleration
• Engine stalling or hesitation
• Check engine light illuminated
• Poor fuel economy
• Unusual engine noises (e.g., knocking or sputtering)
• Increased emissions

Diagnostic Steps

1. Scan for error codes using an OBD-II scanner to identify potential trouble codes.
2. Inspect the air intake system for blockages or leaks.
3. Check the fuel pressure to ensure the fuel system is functioning correctly.
4. Examine the throttle body for carbon buildup or mechanical issues.
5. Test the ignition system components, including spark plugs and coils, for wear or failure.
6. Inspect the exhaust system for restrictions or damage.

Solution

1. Preparation

• Gather required tools and parts.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent any electrical issues.

2. Inspect and Clean Air Intake

• Remove the air intake duct to access the throttle body.
• Inspect for debris or blockages in the air filter and replace if necessary.
• Clean the throttle body with throttle body cleaner using a soft cloth and a brush.
• Reattach the air intake duct securely.

3. Fuel System Inspection

• Use a fuel pressure gauge to check the fuel pressure against manufacturer specifications.
• If pressure is low, replace the fuel filter and inspect the fuel pump for proper operation.
• Check fuel injectors for clogs; clean or replace as necessary.

4. Ignition System Check

• Remove the spark plugs with a spark plug socket and inspect for wear.
• Replace spark plugs if they are worn or fouled.
• Test ignition coils with a multimeter to ensure they are functioning correctly; replace if defective.

5. Exhaust System Inspection

• Inspect the exhaust system for any visible damage or restrictions.
• If a catalytic converter is suspected to be clogged, perform a backpressure test and replace if necessary.