I just passed smog on the vx, i was running out of time with the registration. I made another attempt to keep the ecu from going into lean burn. I failed again, so i just had another cat welded onto the car. I used a Honda Ridgeline cat. I installed a new cat on the Ridgeline because the car ran over a log and it dented the cat. The insurance company wanted it replaced. I kept the old one, the outside was dented but the core was not broken.
If i had more time i think i would have tried a different approach.
I dont notice any difference with two cats on the car.
This scenario would give you high CO. The difference is CO is unburned fuel, HC is partially burned fuel.
I wouldn't blame lean-burn or 12 valve mode being that Honda sold how many VX's and yet they all pass smog? It clearly is not a design problem but a maintenance problem.
Get a valve adjustment. If that doesn't solve it then either your compression is low or you have an ignition problem. If you rebuilt your distributor you still have the same cam/crank sensors. Try another distributor. The Z6 shares the same distributor as the Z1. Perhaps you can find one in a junkyard.
Just an update- I was experiencing similar symptoms as rx7will (see my post, #18). After replacing plugs, wires, 02 sensor, and cat, I found that my timing was severely retarded (5 deg. BTDC!!!). Set it to the stock 16 deg BTDC, and voila! The low power, hesisation went away and it passed smog without any problems.
I'm loving my VX now. It feels so powerful! Hahaha!
hmmm wow. bad laf here too or i soldered a wire wrong(cheap buttconnected one from egay). hopefully my replacement 1 will do it. additionally i'm going to 2 kitties. An old VX/cx oem cat up by the head & a new cat welded after the B-pipe connection. glad some are passing . mine is federal ecu and jdm d15b Vtec-E. I'll be changing the jdm IM also cuz it looks like a dx/ex IM with a bigger TB for sure. I bet the more air =more fuel even with that 49state ecu. post results after i retest in a few days.