Engine Malfunction Indicator Lamp (mil)?

[GaryXT3]

Whilst driving in the most remote and inaccessible spot imaginable on the Outer Hebrides a few days ago the engine MIL warning light came on (2004 vvti 2.0 RAV4), car continued driving with no noticeable change in performance, but stopped the car and phoned my local dealer (for no other reason than their telephone number is printed on the number plate!!), their advice was not to drive the car as I risked wrecking the engine, which considering my location wasn't really helpful. Ignored their advice and drove on (hadn't really much choice!!), and the following day the light went out. Managed to find local garage who, although didn't have code reader for car, reckoned that as car was driving OK and that as light had gone off that it was probably a non-critical intermittent fault, and that it should be OK to continue journey, and 350 miles later I've made it home (and the light's still off). A few questions...

- As the light has reset, and as there has been no re-occurrence, is it reasonable to assume that there is nothing too serious to worry about here? Will the fault condition still be stored, or after a few days of start/stop driving cycles will the fault code now be cleared?

- As the car is now 5-years old (and I've no plans to change the car just yet), a code reader is probably a worthwhile investment, are all 2004 Toyota's OBD2/EOBD compliant, and is this ISO, PWM or VPW protocol options, and can anyone recommend a reasonably priced hand held code reader?

- The engine MIL indicator comes on when the ignition switch is turned to the On position, and goes out immediately when the engine starts, is that normal, or should the indicator go out after a few seconds without starting the engine (same as the SRS and ABS indicators)?? Funny how I've driven the car for 5-years now without really paying attention to the test sequence here!!

Any advice/help appreciated...

Regards,

Gary

[pmb]

Sounds like the standard failure of an O2 sensor at five years. Don't understand why any garage does not have a code reader. There will be a white socket under the dash below the steering wheel to connect an OBDII reader to. 20-30 quid for one. Several threads on here about this. It will probably come back , usually the heater circuit goes o/c. Only 250 quid from Mr T.

[anchorman]

It will have stored the code and as pmb says probably dicky 02 sensors.

Get one of these and read it yourself;

http://cgi.ebay.co.uk/UNIVERSAL-OBD2-II-CA...%3A1%7C294%3A50

We will tell you what the code means.

[GaryXT3]

Code Reader's displaying Stored Code P2238 (O2 Sensor Positive Current Control Circuit Low Bank1 Sensor1), is this indicating terminal fault, or should I instead just erase code and see if it re-occurs? MIL light is still off (even though code is stored) and car's still driving OK, and as car passed MOT yesterday evening I'm assuming there's nothing impacting emissions here?

Advice appreciated...

Regards,

Gary

[anchorman]

Its up to you Gary.

These 02 sensors often play up for some time before they put the light on permanently. Now you know it is the top sensor you could try leaving it and see if or when it does it again. I think that is what I would do.