My 1998 Chevy van run rich at idle.
Failed 2 smogs. Only drove 2 bocks for the 1st. 2300 ppm at idle. dove
freeway for 10 minutes on 2nd smog. Engine temp about 140. down to 1700
ppm. Needs to be below 1000 ppm. Was engine cold or oxygen sensors bad?
I'm assuming that the 140° is F. Correct? If so, that's why it's running rich. You need to be at normal operating temperature of at least 195°F to pass the smog test. If your Express won't get up to 195°F replace the thermostat. It's stuck open. HTH. -Jim
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