My 98 Boxter check engine light is on. After I took the car to the mechanic he found faults P0410 secondary air system and P1411 manufacturer control emissions. He said he tested secondary air system, found air pump not coming on, he traces wiring and cleaned all connectors, pump ran, then tested air pump control valve, it was not operating. He changed it. He charged me $600. I brought the car back home and check engine light came back on. I am planning to take the car back to him. Any suggestion as what causes this problem. Thanks.