Crossover tube is fed from smog pump. During warmup, the smog pump injects fresh air into the exhaust ports to help the first pair of cats "convert" more efficiently.
When the car warms up, the bypass valve on the rubber hoses on pass side closes, and the diverter valve reroutes air from smog pump to the h-pipe to the second pair of cats.
Basically, with a crack here you have an exhaust leak, which can contribute to your lean/rich condition codes.
It may not be the complete source of your issues but it's worth addressing.
Sent from my big ass iPhone 6 using Tapatalk
When the car warms up, the bypass valve on the rubber hoses on pass side closes, and the diverter valve reroutes air from smog pump to the h-pipe to the second pair of cats.
Basically, with a crack here you have an exhaust leak, which can contribute to your lean/rich condition codes.
It may not be the complete source of your issues but it's worth addressing.
Sent from my big ass iPhone 6 using Tapatalk