Just had a strange one this evening, which I would appreciate feedback on...

Just sauntering along, not doing anything impressive - just daudling at 70 or so along a DC, and the CEL came on. Prodded at the SECS to see P0420 (Cat below efficiency threshold). Didn't worry about it.....

Then, 10 mins ago, decided to clear it - so thought rather than doing an ECU reset on the SECS I'd see if it cleared with the 3 starts method.... It didn't..... Even tried 4 or 5....

So, with engine running on the 5th attempt I did an ECU reset through the SECS. Then killed ignition and restarted.

Initially, the CEL was off, and then within about 10 secs the CEL came on again.

However, this time the SECS said 0 current codes and 0 historic. Tried killing ign and starting again - same result: CEL on, 0 current, 0 historic.

Did yet another ECU reset, and it has now stayed off.... for the time being.

Any ideas what the ghost CEL was - or why this happened?????

Shades