I believe he's wrong. ECUs work or don't work, there's nothing between.
It's likely to be a knackered sensor feeding duff information to the ECU.
What's the Ka's mileage and how is it used? The oxygen sensors typically fail anywhere between 40,000 miles (city) to "over 120,000 miles" (motorway), and this would be the favourite sensor.
55,000 ish.
The car failed it's MOT on emissions.
Well that answers the question properly, doesn't it?
Peter
Well there are exceptions to that but it's almost infintely more likely to be the O2 sensor.
Would the O2 sensor make a big difference to the emissions and the petrol usage?
Petrol usage has gone up quite a bit recently..
The message from "Moo" contains these words:
Very much so. Lamda sensors usually fail in such a way as to make the engine run very rich (the computer sees too much oxygen in the exhaust stream and pumps in more fuel to compensate).
Yes - because the ECU is enriching the fuel:air mixture. Basically, it's a bit like running with the choke on - you'll see a significant increase in fuel consumption and eventually you'll bugger the cat.
Where are you based? My OBD-II Scanner would show that the O2 sensor isn't working - we're in York...
Yes that's normally what indicates that you need to change it. You can confirm it with an oscilloscope .
Didn't realise the O2 sensor was called a Lamda sensor.. that has already been changed. The problem is still there.
Is it getting heater voltage & are the connections good? Is the coolant temperature sensor working?
The message from "Moo" contains these words:
Lambda - my typing was being helped by a small girl.
I'd still suspect the temperature sender.
Really? There are two sensors... when was it changed?
It was changed as part of trying to solve the current problem.
Right.
Perhaps a summary of what happened, when, and what was done, would be useful for us?
Check for heater volltage at the o2 sensor and a good earth from exhaust system to chassis. Then check CTS voltage during warm up. It is warming up right? If you suspect its not entering closed loop running- monitor o2 sensor voltage, then introduce a vacuum leak- look for a go rich signal, then use an unlit propane torch in the inlet and look for a go lean signal.
Your ECU is fine, trust me, you have a sensor or wiring problem.
Tim..
Will only be one sensor on a pre 2002 Ka.
If it was a 2002 on Ka with a primary o2 sensor fault, then the MIL lamp would be lit anyhow. OP doesnt mention this.
Tim..
We've an '01 with two sensors....
ooooo, I was sure it was only 02 MY cars onwards. Perhaps yours is a 2002 model registered in 01??!
Tim..
Unlikely 'cos he was first registered in February 2001... Time for a survey I think! :)
What's that then? A car that's been sitting in a field prior to first registration for a negative amount of time? :-)
Peter
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