Can an Oil Change for a Mercedes C300 Trigger P0170 and P00173? Causes and Fixes Explained
I recently performed an oil and air filter change on my Mercedes C300, and about 40 miles later, the engine light activated with diagnostic codes P0170 and P0173. These codes indicate fuel trim issues — specifically, a lean condition in both the left and right banks of the engine. I'm wondering if the oil or air filter change could have caused this. Could improper installation, such as a vacuum leak or restricted airflow, be responsible? As someone new to German vehicles, I'd appreciate expert feedback on whether these codes are directly linked to my maintenance work or if they might point to another underlying issue.
Did you install the air filter correctly? An improperly seated air filter can create a vacuum leak or restrict airflow into the intake system. Both P0170 and P0173 relate to fuel trim — one for the left bank, one for the right bank — indicating the engine is running lean due to an imbalance in air-fuel mixture. For more details, see: https://www.obd-codes.com/p0170