I know AWD in perth can do a CEL light fix by soldering in a small add on that reduces the voltage some how and prevents the CEL showing for this fault
Would be worth contacting them to discuss very friendly and helpful people, im sure it wasn't expensive either
Here's there contact details:
AWD Motorsport Engineering
Unit 5, Inveralmond Way,
Inveralmond Ind. Estate,
Perth, PH1 3UQ,
Telephone: 01738 633336
Email:sales@awdmotorsport.co.uk