Last yeyar I had an Ecotek Powerboost engine clean on my 2003 Hijet for the first time. The van had very low mileage 12,000 miles from new. Two months later the MIL came on when I switched from LPG to petrol after a few miles. This happened every time I switched from LPG to petrol. The moment I switched back to LPG the MIL went off. Has anyone one had a similar problem with or without using Ecotek. Any ideas on the problem would be welcome.