I agree. But in my case after a good old Google it was just the sensor on the cat. When it comes round to the MOT i'll have a new one on there for a nice pass until then i'm happy with the cat melting its insides away. Saves me the hassle of removing it completely. Many thanks for the replies - I'm guessing the answer to my question is yes. I didn't make it perfectly clear that I was unaware if my 2002 IS200 SE is too old to have a point for the diagnostic computer to be plugged into.
Newbie and Know Nothingbie......any help greatly appreciated. My check engine light has appeared for the very first time since I owned the car (6 years and 40,000 miles) so I'm unsure if I need to take it to an official dealer or a regular mechanic to diagnose the fault. The car appears to run ok for the very journey I did to get it home.