Just a quick word of advice based on my out of pocket experience:

If you have a yellow light on and the car is using 20% more fuel AND is over 40k miles OR you haven't had a new oxygen sensor for 40k miles then the probable cause is the sensor as they only last 40k miles approx, once the sensor dies the cars brain runs of default settings - hence the 20% more fuel use.

DON'T pay you local Mitsubishi dealer to read the fault with his machine - he will charge you about £45 plus vat PER GO - a fault fix may need several go's

DO Buy a OBDC reader from ebay for about £35 - Mine is a CAR CARE u480 CAN OBD2 AUTOSCANNER car diagnostic tool - this box will also allow you to turn off the yellow light
(which will re illuminate again if the fault remains) it has a error code book that will take you to the faulty part

Also you can reset the yellow light by resetting the whole electronic ignition unit by simply removing the red + battery lead for 10 seconds. (again expect the light to illuminate again after a few minutes ... each time ... that is until the actual fault is resolved)

ALSO Mitsubishi wanted £130 for a new Lambda oxygen sensor - I found one available from the NGK replacement oxygen sensor catalogue HOWEVER the correct one for ENGINE 4G92 was incorrectly listed against the 1.8 engine anyway buy this part - its about £48 to £78 once you have found a supplier for NGK Oxygen sensors
don't fit a generic one as i did they DO NOT WORK , they all have specific amperages and heat tolerances - you cant just use anything THIS IS THE CORRECT PART

NGK Oxygen Sensor Part No NGK 0ZA448-E53 Stock No 0448 Book Ref 460000448010

well looks like that might save someone about £150 on their dealer bill.

Oh finally the sensor is on the outlet manifold, it looks like a spark plug, you can buy an open sided socket from ebay to fit these with to protect the wiring.
it takes 10 mins
> disconnect its connector block > wrench out the old one >
wrench in the new sensor > reconnect the connector block > DONE
fitting is the same as with plugs - wait until threads are just about biting then wap it in 1/4 of a turn - no more.

SHARE THE KNOWLEDGE !!! SAVE A FORTUNE

:banana: Thankyou mymail 1964, for taking the trouble to list your experience.
The engine management light on my 2002 Carisma 1.6 Mirage (41,000 miles) has just now decided to show it's self and my wife tells me that the fuel consumption has noticably risen, so your comments for me are well timed.
I will take your advice. and seek out the NGK sensor you have listed.
Are you also able to guide me to the OBD2 connector position ?
My thanks. Emrock.

:beer: Thankyou for your advice, have managed to obtain the sensor for £50 from EU Exhausts and will attempt to fit it this Friday.
Will update with the result when done.

is this the one that's located at the bottom right near the air filter, battery and fan?

I had changed recently the oxiden sensor for my car to Bosch 0 258 005 133 -sensor at 38$ from VAZ 2110 /
All works fine. I only soldered the wires from contact part of old sensor to wires of new sensor and deleted the mistake with my OBD II scanner /