Hi guys.
I've got a 91 accord Exthat's been sitting for some time. I took it in last week to do an E-test and it failed miserably
Changed the plugs,filter and the oil, reset timing and ran the snot out of it before taking it into the test.

Now the car has passed every test except the high Idle co% - which it failed by almost double the allowance.
I'm not getting any fault codes displayed or brought up when I jump the diagnostics port ( blue connector).

Does anyone have some suggestions on what I might want to try next ?
I was thinking cat and O2 sensor. Anyway to test them out?

 

http://www.troublecodes.net/articles/smog.shtml

 

Thanks for the info.