I have spent a couple of hours searching the forum on this and couldnt find a solution for this code on my 88 california 5.0 KOER test is giving me a code 44, Secondary air injection system inoperative (right side). Code 44 and 94 together usualy mean the Thermactor system isnt working properly, but a 44 on its own seems to mean the secondary air is being diverted just fine on the drivers side but not on the passenger side. My understanding is the thermactor air going to the back of the cylinder heads is not registering with the O2 sensor on the passenger side. I have tested the TAB and TADs and they are functioning properly and the smog pump is putting a good amount of air. I evan went so far as to pull off the pipe going to the back of the cylinder heads and blow compressed air through it and found it was not clogged. At this point the only solution I can see to this code is that the passages in the cylinder head itself is clogged, preventing the thermactor air from entering the exhaust system. Am I missing something? Where exactly does the thermactor air go once it enters the back of the cylinder head and where does it exit into the exhaust? Has anyone ever had this problem before and any suggestions on how to fix it without removing the cylinder head from the engine? I know it only diverts when the engine is cold but having any trouble code is bugging me. The o2 sensors have less than 5000 miles and I had the stock heads rebuilt before this problem started. I have found some great info on this forum, including the following explanation of how the secondary air system functions.