failed emissions test

1991,crx,hf.
it failed emissions testing. low idle numbers are just a little out of specs.
any suggestions on how to make it pass ?

Heat up the catalytic converter right before you test. Take it for a long highway run to make everything hot as it can be, and keep revving the engine while you are waiting to test to keep it hot (if the guy doing the test will let you rev up in front of the testing station - heating up the cat isn't allowed and if an inspector caught him allowing people to rev up he'd probably be fined).

The hotter the cat is the cleaner your exhaust will burn.

assuming the idle is low, screw it back up to specs and retard the timing. assuming there are no CELs, take her back in.

i sprayed intake cleaner in mine, change the oil, new plugs, set timing to stock, changed pcv valve and that did it for me.


Oh and changed the O2 sensor.