I have a 2005 S Type 2.5V6, it is a Japanese import and today has covered 39k miles.
last Autumn after leaving the car at an airport for a week or so during the drive home the car went into restricted mode and had a misfire.
Garage said water had got into the plugs somehow, so these were changed and all was ok, then the dreaded warning light came on with a P0420 code.
Garage told me it was the catalytic converter, drivers side that needs replacing. I tried cleaners and E5 fuel but the light kept coming on.
bizarrely the car has now passed its MOT with the warning light still on, another garage has changed one of the lamda sensors and has now done a diagnostic test, this showed both cats ‘pulsing’, they’re going to do a smoke test this week to check for air leaks
does anyone have any ideas please? Is it likely that both cats have failed? If they have what should I do?
best Julian