Gasoline Engine Management: Systems and Components (Bosch Professional Automotive Information)

This book gives me new information about emission-control systems and diagnostic systems.

Well written, easy to understand, and very informative. The only reason I did not give it 5 stars is that its a bit dated, I'd be interested to see how things have progressed 10 years on (or even if they have!) I'd recommend this book to anyone with an interest in automotive technology.