I've been working with my mechanic for the last month trying to resolve the P0410 check engine code in my 1998 V70 XC Wagon. The secondary air pump always runs fine when the car is first started. Where the check engine light goes on is after the engine has worked hard, say climbing a hill or driving on the freeway, then coasts awhile downhill or idles at a stoplight. The mechanic has now replaced the relay and the secondary air pump, and I was giving it one more day to reset before taking the car in to get its smog check when the check engine light went on again idling in traffic on my way down from the mountains.

If anybody has any ideas as to what else it could be, I'd be most appreciative. I'm throwing in the towel with my mechanic and have an appointment at the Volvo dealership next week. They haven't seen me for awhile, and I'm sure they're going to want to make up for lost time. Thanks.

 

The mechanic should have replaced the Valve first:
http://www.eeuroparts.com/Main/PartD...spx?id=9125623

Also replace:
1. Valve Gasket:
http://www.eeuroparts.com/Main/PartD...spx?id=1271764

2. The vacuum hose feeding the valve.

 

Thanks. Took it into the dealer and they told me that the "diverter valve" had to be replaced at the same time as the air pump. They told me i needed a new pump, even though my mechanic told me the pump itself was probably okay. I let them do it because I just can't mess with it anymore. Hopefully it's fixed, but I won't know until I drive it for awhile.

 

i am having this same problem and i was wondering if your issue was solved by this valve replacement? please let me know if it was the same part as listed above and here:

thanks!