The ecu light and power loss can be a multitude of things. The 2.2 is less susceptible to the injector faults that the 2.0 commonly suffers and the usual suspect of this behaviour is the EGR valve which once blocked gets stuckand either can't open or close fully which sticks the warning light on and drops the power to prevent engine damage.
Use the Worldwide Diagnostic System (WDS) to interrogate the Engine Control Module (ECM) for DiagnosticTrouble Codes (DTC). DTC P1582 will be logged if a fault has occured with the Throttle Position Sensor . This is not a throttle fault code, but is used for information only. (See Technical Bulletin XT303-01.)
V6, 2.5 Liter. Horsepower. 192 @ 6800 RPM. Torque. Don't buy a car with unseen problems. Get a full history report and be confident in your purchase. 2004 Jaguar X-Type KBB.com Consumer
However, the launch of a lower-cost front-wheel-drive X-Type in May 2002 spoiled the party. All-wheel drive X-Types come with a V6 petrol engine of 2.5 or 3.0 litres. The front-drive models have a 2.1-litre V6 (confusingly badged as a 2.0-litre to dodge some sort of road tax in the UK.)
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