I have 2 CELS. 16795 is for the secondary injection system. I had my mechanic
smoke test this system. He replaced a hose that was leaking.
17887 does not exist. He replaced a valve near the vacuum brake booster.
I could blow both ways through the origonal valve.
10 days after replacing the hose and valve both codes returned.

17886 deals with the leak detection pump. Might that be why I'm getting 17887?

My car now has 151K mi.