Engine light on Mazda 323

The engine light on my Mazda 323 [2001] comes on intermittently [since Aug]. The garage says it is prob the sensor but it might be the computer. A new sensor is on order since yesterday. Fingers crossed HARD.
Anyone know how reliable MAzda computers are? And how worried should I be?
and :sad:

if the garage run a dtc check they will know which sensor ,very unlikely an ecu mazdas arent bad with that kinda stuff more than likely cat related

Hi, Ford
It is the computer sensor.
Plus I am on the waiting list for my NCT. : 0 (
Is the cat expensive?
What is ecu?

the cars computer is called an ecu or pcm it contols all the engine functions,the most common problems are usually emisson related ie cat or lambda sensors but when the light comes on a fault is stored on the ecu and will direct you towards the the sensor which is reading incorrectly this is a simple diagnostic procedure .you just need the right diagnostic equipment does your mechanic have this or is he just guesing

Mazda main dealer so they should have all the diagnostic equipment necessary to reduce need to guess.

Now I'm really getting worried.

Don't be worrying, with intermittent faults nothing is stored in the ECU on most cars, very few record everything. It could well be down to when you run low in fuel and fill up you bring the dirt etc from the bottom off the tank to the top and end up burning that. The car picks tht up and light comes up.

Best thing to do before you start buying a sensor would be not to let the tank go before 1/4 empty and fill it when it gets to that marker. Try this for a few fills and see if it comes on. If it does you have to look further but this way cost you nothing.

What type of car have you got and I'll look into it over the weekend.
Petrol or Dsl?

Petrol engine.
Over half full today but light came on. Not very reassuring, I'm afraid.

The light came on when the tank got to 3/4 level. ???

Anyway, the garage fitted a new sensor today and the problem is solved[I hope!]
Thanks for replying.