can any one tell me as to why my cat light comes on, its mainly in the morning but do sometimes come on going home to.:headvswal

It means the Cat is overheating...which will be becuase unburnt fuel is burning off in the exhaust system. General overfuelling (from bad o2 sensors, temp sender..etc) can cause this but its typically becuase one or more of the cylinders is misfiring(not igniting the fuel).

 

Missfire can be a fault in any part of the ignition circuit - Its more often than not the PTU or Coilpack connectors but can also be the PTU or Coilpacks themselves or the wiring loom inbetween.

Thanks very much for your reply.i was told last year that my car had two lazy o2 sensors which probably is the reason.also i did run it on four star fuel a year or so ago for about a month that probably did nt do it any good im thinking about de catting but aint to sure what do you think thanks again bobbyzx

Do a search on "decat" lots of pro's and con's although many peoples cars have been fine (including mine ;)) it's up to you at the end of the day and what you "might" expect to need fixing in the future