These codes indicate secondary air isn't reaching the catalytic converters at 'cold' start up. Several things can cause this to happen. It could be the change over valve isn't opening or there might be a leak in the vacuum system itself. If replacing the valve doesn't work, leak test the vacuum system to see if it hold vacuum. It could be a cracked tube, a hose connector, or the vacuum tank itself. It could also be a cracked oil fill tube or a cracked dipstick tube.
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