Engine or trans...?

Took a road trip last night for an engine for my race car. On the way down whenever i would climb a small hill, the check engine light would start to flash. The truck would loose power, almost like the computer put it in limp mode. Once im on level ground the light stops flashing and becomes solid, and power goes back to normal. However it only does this on the highway. Never around town, or even on back roads doing 45mph. I ran the codes not that long ago and came up with

P0410 - Secondary Air injection malfunction

P1416 - manufactured controlled aux emissions.

The book says when the SES light flashes there has been missfires, the truck runs as smooth as it always does. I'm going to run them again today, I'll post when i get them. Any ideas? Thanks all.

Could be a problem with water in the air pump or a bad air pump. See the attached TSB.

http://www.acdelcotechconnect.com/pdf/tsb/tsb_04D-183.pdf