When the check engine light pops on, it can feel like the technician is speaking a different language. In this episode, Dave and John break down one of the most common — and most confusing — concepts in modern auto repair: fuel trims. We’re talking what they are, why they matter, and how they can reveal what’s really going on under your hood.

You’ll learn:

• What “lean” and “rich” codes actually mean

• Why your engine constantly adjusts fuel delivery

• How shops diagnose fuel delivery problems the right way

• How understanding fuel trims can prevent unnecessary repairs

Whether you’re a DIY’er or just trying not to get taken for a ride, this episode will put you in the know the next time you visit a repair shop.