You can try flushing it, but if that doesn't work then you will need to replace it.Context
The secondary air injection check valve thingy in US and Canada etc where trailblazers are usually most sold and driven is around 70 usd
altho here that thing is 500 USD and NO WAY IN HELL I'm willing to spend that much
I wanna know if it is repairable I'm getting this code
P2431 Secondary Air Injection (AIR) System Pressure Sensor Performance
By the way, there are several versions of these valves. Be careful when ordering a new part.