i reckon it's your oxy sensor, but without having to search for the relivant thread, this is how you can find out.
down by your passangers feet, just on top of the kick panel(cpu behind this) their should be a female plug, just hanging in the breeze it should look somthing like this
now that picture is if your looking at the plug. now you see holes A and B???
make sure your car is off, get a paper clip or somthing metal and bridge (short) between a and b holes. now turn your car to ignition (do not start!!!) and have a look at your engine light. now you need to count the flashes, it will give short quick flashes followed by a pause then some more short quick flashes.
yiou need to count the short quick ones,
say it flashes
(1) (3)
flash.............flash.flash.flash
that would be code 13
say it flashes
(4) (1)
Flash.flash.flash.flash..............Flash
that would be code 41, get it???
it will repeast and if you have mroe than one error code it it will do them in seqence.
your fan will come on and this is normal , dont be alarmed. when you find whats wrong, get back on here with the code
lol, it could mean a million things...do a diagnositics test (there's instructions on how to on this forum) and get the fault code to find out whats up.
Yeh it's code 13 oxygen sensor,you are spot on csl.Now to find the sensor.
At the moment the fuel economy was pretty good i thought, about 600 k's from a tank of fuel.