October 30: LEMON manuals on a temporary server, it is slow and having issues, download the manuals you need! Later in November we will switch back to the fast server.

Theory & Operation

NOTE: This article is generic in nature and all information does not apply to all vehicles. For vehicle specific information, see the appropriate articles in the ENGINE PERFORMANCE category.

This article covers basic THEORY & OPERATION of engine performance-related systems and components. Before diagnosing vehicles or new systems with which you are not completely familiar, read this article.