Replaced oxygen sensor but dash light still on...

[x Wilco x]

Replaced the oxygen sensor in my Renault Clio due to dodgy fuel damage but the 'Exhaust emissions warning light' is still showing on my dashboard.

Car runs fine with new sensor and had to wait ages to get hold of one but this damn light will not go out! No other obvious symptoms etc...

Any ideas?

[Sus1e]

Was the fuel completely flushed out of the system - tank drained and fuel flushed through the engine? If not, that is the first thing I would try.

I would also get the garage to look at it, as it may be that the light/ECU needs resetting.

You should be able to claim all the costs for this back to the place that sold you the fuel.

Hope this helps you

[x Wilco x]

All dodgy fuel gone and car, with new sensor, running fine...

Mechanic said light will re-set itself after running for a few miles as management system has to re-calibrate (or something). Any ideas how long this should take?

Can obviously call mechanic back but if it's something that can be sorted easy/or will sort itself then that will be better! Will disconnecting the battery reset the ECU?

[Sus1e]

I would try disconnecting the battery and leaving it for a while (30 mins or so) to see if that sorts it out.

If not, it may need to go to be cleared down at the garage.

How old is the car? This may have some implications on what to do.

[x Wilco x]

2003 on a 53 plate.

Will disconnecting the battery cause any other issues?

Cheers for your help...

[Sus1e]

Disconnecting the battery shouldn't cause any other problems as it would be just the same as if the battery was dead.

As it is a fairly new car, the garage should be able to clear the light using their diagnostics tool - something like a laptop which the plug into the ECU to check for error codes and clear them down.

I would try disconnecting the battery for a bit (do it for 10 minutes if you are worried about the time) and if that doesn't work, take it to the dealer (a main dealer has better access to the diagnostic equipment) for them to try and clear it down.

If this doesn't work, and driving it around for a few weeks doesn't work, you may need to go to an autoelectrician specialist - see your local yellow pages.

[x Wilco x]

Disconnected battery for a couple of hours and rang back mechanic. Light is still on, on the dash - he says it may take a good few days to reset...

Should it really take that long? Am I just being paranoid???

[Sus1e]

It may do, as there may still be some tiny traces of the fuel in the system.

I would run it for a week or so and see - TBH the mechanic should know best.

[x Wilco x]

Light has gone out... All on it's own!!!

Lets see if it stays out! - Cheers...

[Sus1e]

great news, glad it got itself sorted