Volvo C70 Problem Report
Volvo C70 Check engine light is on due to secondary air injection system
If the check engine light is on and diagnostic trouble codes point to the air pump system, then the entire system needs to be checked.
There are a few issues that arise from the vacuum lines becoming plugged or disconnected but the most common issue is the air pump itself fails. The reason the air pump often fails is from a defective air pump check valve that allows exhaust gasses to contaminate the pump.Replacement of the air pump and check valve is necessary to address this issue.
One thing to be aware of: If the problem is not addressed eventually these exhaust gasses can contaminate the MAF Sensor and Oxygen Sensors as well, causing the engine to run very poorly and cost much more to fix.