Lambda light 850 t5

[02GF74]

an update in case it helps anyone else.

I was convinced it was O2 sensor and decided I was not going to be crawling underneath the car so took it to the garage.

It turned out to be breather issues. There is a small diameter plastic tube (most of this stuff being 30 years old is brittle) that runs across the front of the car - this had broken and I fixed it with tape - but clearly the repair failed.

There is another breather tube near the throttle - the right angle piece fallen apart and I had repaired it but clearly too that had failed.

When I drove it from the garage the idle rpm was about 100-200 lower but after a drive on the motorway today, that seems to have cleared up. I reset the mpg and am seeing numbers in the upper 30s so that looks good as well.

I don't know how they managed to reset the EM light (and no, it is not disconnected!)

[nickm]

As I said a vacuum leak

Depending on the ECU reset can be done with a LED and a paper clip or under the bonnet port. Or when fixed 2 or 3 drive cycles.

[Baffler]

Originally Posted by nickm

As I said a vacuum leak

Depending on the ECU reset can be done with a LED and a paper clip or under the bonnet port. Or when fixed 2 or 3 drive cycles.

Nickm was on the money!

Originally Posted by 02GF74

I don't know how they managed to reset the EM light (and no, it is not disconnected!)

Indeed, once the fault has been rectified the ECU no longer has reason to bring on the EML. In some instances several start/stop cycles of the ignition can clear the error although the DTC will remain stored (historic) until such time as it's manually deleted using a suitable/capable device.

Happy days!