Malfunction Indicator & Cat. Converter

May 27, 2011

Hi all.

Found this forum just before I picked up my new (to me ) Avensis. - What a great place!

Have had my 55 plate (39k miles) T3 VVti 2.0ltr Auto for a fortnight now. Got from the local Toyota dealer with full service history and a years warrently, as completey clueless when it comes to car maintenance!

Generally very happy with it so far.Just wondered about the following couple of things though:

1) A couple of days ago the Malfunction Indicator Light came on. I'd driven it just 4 miles, stopped for about 2 hours, driven a mile; stopped again breifly - it came on at this last start up, and stayed on for the 4 mile journey home. Was still on later that day when I turned the engine to check. The following morning it was off.

Got a friend to check the code, and it was one of the cat. convertor censors that had set it off.

My question is, was it the short journeys that may have made the censor activate, or could I perhaps have an underlying problem with the cat?

I do a number of these short 4-8 miles journeys, interspersed with longer 30+ to 120mile trips. Any views would be aprreciated.

2) Have read all the horror stories on here about the Avensis burning/losing oil issues. Is mine one that may fall into that catagory? I do nomramlly check the oil about once a month, and my old Honda Accord used to drink a little oil (perhaps a litre between services).

Should I be checking the oil when hot or cold? I always used to check cold with my old car, but I see in the manual it says check when hot. To my un-educated car maintenance brain that makes no sense, as surely there will be oil still around the engine if checked when warm??? Don't want to check at the wrong time, and end up over filling it...

Finally, what are your views on having an oil change between services? I've not done that with my previous cars, but have seen it mentioned here a few times.

Many thanks for all your help.

May 27, 2011

As regards checking the oil - as you have an Automatic, there will be 2 dipsticks. The engine oil will have one and there is one for the auto transmission fluid.

You should always check the engine oil with the car parked on a FLAT surface rather than a hill or other slope. Always check the engine oil when the engine is cold and wipe the dipstick with a rag before re-inserting it to check the oil level.

As regards the transmission dipstick - its a good idea to check this with the transmission warm, say after a run of a few miles. Bring the car to a stop and leave the engine running - open the bonnet and remove and wipe the transmission dipstick. re-insert it and then withdraw it - read the level on it. It should be between the min and max marks with the engine running and the selector in "Park". fluid is added through the dipstick tube using a suitable funnel.

Without the fault code that was obtained from the ECU by the code reader, cant really advise on the managemnet light coming on.

Normally, any code relating to the cat convertor is triggered by one of the lambda sensors, and could be due to a faulty lambda sensor, an oil damaged catalytic convertor, or even a malfunctioning airflow meter.

As for oil changes, that depends on you really, but personally, I do them every 6000 miles or once a year (whichever comes first), as oil changes are good for the engine and are relatively cheap to do.