So I have a 1994 prelude with an h22a 9:1 compression, egr ports were cleaned a couple months ago and I just did a full tune up (o2 sensors, cap/rotor, wires/plug) and I literally had my cat replaced yesterday and this is the third time I failed smog and my temporary permit is about to end. The first time I failed smog for high everything, then 2nd time I added some guaranteed 2 pass stuff and I failed again but it made it worse, gross polluter on both 15 and 25 mph and now today after tune up and replacing cat, I failed by being gross polluter on HC and CO on 25mph only




First test





3rd test after replacing cat and full tune up

 

clean injectors, iacv, fitv
check vacuum/exhaust leaks
new air & fuel filters
adjust valves & idle
check timing
change oil

 

You need to adjust your ignition timing to within spec, and then adjust your idle.

 

Depending on how far off your ignition timing is, it's possible bringing it to -15 will make you pass.