Failed Emissons 88 Fox Pls Help

The first time both HC and CO were high. I adjusted the timing down to spec, 6 degrees, and I turned the screw on the side of the intake in about 3/4 turn. The HC came down to just about spec but the CO went up even worse. I assume the HC was related to timing but I realize I don't know what the screw on the side is for. Any help would be appreciated.

the screw on the intake is for idle speed, lowering the idle usually makes the CO run a little richer. Mixture is adjusted at the 3mm allen screw between the fuel distributor and the air boot. You might want to take this to someone who knows CIS-E fairly well. They can adjust CO% and check O2 sensor operation at the same time.

Thanks for your reply. It turned out to be that the cat was hollowed out. A used cat solved the problem.