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[chrisr]

As an update to this I can now switch off the check engine light start the car and it will warm up on tickover and run without the light coming on, have had it runnning for up to 45 minutes, but if I drive anywhere the check engine light comes on after about 10 minutes. I have checked connectors and fitted a new after cat lambda sensor and new plugs, and run a bottle of Cataclean through.

[TheBoy]

What are the trims doing?

[chrisr]

Sorry I don't understand the question

[Doctor Gollum]

Sorry I don't understand the question

On the live data, you should see LTFT and STFT these are the long term and short term fuel trims respectively.

These give a clear indication of how the ECU is managing air and fuel.

[chrisr]

I will be taking the car to a friend who has the equipment and the knowledge about these things, hopefully he will sort it out. If not I'll be asking some more stupid questions! I shall be passing Brackley on my way home on the 18th May should you be available Mr The Boy.

[TheBoy]

I will be taking the car to a friend who has the equipment and the knowledge about these things, hopefully he will sort it out. If not I'll be asking some more stupid questions! I shall be passing Brackley on my way home on the 18th May should you be available Mr The Boy.

LOL, sods law, I just booked some flights, and will be away, assuming it doesn't all kick off again.

[chrisr]

No problem, hopefully my mate can sort it.
Another update, after turning off the check engine light I started the car this morning and drove in to London, a distance of about 16 miles and lots of traffic, I got to my destination and the light was still off but when I had to restart the car to move it the check engine light stayed on. Does this give any clues as to the problem?

[chrisr]

Got all the way to Northampton with no check engine light, even stopped at Toddington and restarted the car, got to my mates and restarted 3 or 4 times, he plugged it in and it was still talking lambda sensors. Left his house and as I predicted the light came on 10 minutes later. He suggested I change the pre cat oxygen sensor so I did that this morning and turned off the light. Went for a drive and it stayed off, until I stopped and restarted the engine and then it came back on. So now both sensors have been replaced what do I do next? Car is still running fine and I'm getting 30 mpg overall.

[cam.in.head]

is it the same as the v6 setup (ie a small cat then a main one further down ?)
if so then changing o2 sensors wont work as its not the sensors that are faulty . as mentioned earlier you need to move the second sensor

[TheBoy]

Got all the way to Northampton with no check engine light, even stopped at Toddington and restarted the car, got to my mates and restarted 3 or 4 times, he plugged it in and it was still talking lambda sensors. Left his house and as I predicted the light came on 10 minutes later. He suggested I change the pre cat oxygen sensor so I did that this morning and turned off the light. Went for a drive and it stayed off, until I stopped and restarted the engine and then it came back on. So now both sensors have been replaced what do I do next? Car is still running fine and I'm getting 30 mpg overall.

What were the codes. There are a lot of various different lamda codes. The codes help to pinpoint what the ecu sees as abnormal, the text alongside is the code reading device trying (not always accurately on cheap chinese ODBII ones) to say what the code means. But the code(s) are what we need, ideally with the sub codes if available, though many readers don't provide this (and hence the text is often inaccurate).