the way i see it is the AFM couldnt read the air properly so it kept putting more fuel in, hence the running rich. i cannot see any reason why there would be any damage to the car at all. if anything the plugs might be a bit fouled, but that should clear fairly soon. Or you could take them out and clean them

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2013 Toyota Hilux 4x4 - Weekender
1991 Mazda MX-5 - Fun