Secondary air injection System

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Ah, the secondary air injection system on the C300 – it’s a sneaky one! Since you’ve already replaced the smog pump, kudos for tackling that! The relay for the secondary air injection system can often be found in the engine compartment fuse box. On the C300, it's usually labeled as "AIR" or "Secondary Air Injection." If you're having trouble identifying it, your owner's manual should have a diagram of the fuse box layout. Also, don’t forget to check the air injection check valves and the hoses for leaks or blockages. Sometimes, the issue isn’t just electrical but mechanical as well. A bit of detective work might save you a few headaches! If you need more advice, have other questions, or need to find a certified repair shop in your area, just let me know! Call us at 877-913-1554, and we'll gladly find you a certified RepairPal shop in your area!