jdm swap + smog troubles

i have a 91 civic hatchback. i swapped out the stock engine, and threw in a B16. it took a few tries, but i eventually passed the state BAR inspector's test.

someplace along the way, i lost a distributor bolt, and the damn thing slopped all the way over to maximum advanced.

a while later, i took it for smog, failed (astonishingly high nox, like 3300), checked the timing, set it to where it's supposed to be, and tried again. my nox was lower, but still way high. something like 2400, with around 800 as a pass.

i don't know what to do to fix it. did i burn out the cat when the timing was so far off? do i need to find a throttle body with an egr on it? do i need to find a *COUGH!* smog *COUGH* shop?

thanks

I doubt you'd have hurt the cat with timing way off, but you definitely may have damaged the rings, bearings, and burned the valves with it fully advanced.

Rings would cause blow-by, which would put oil into the combustion chambers, causing a very inefficient burn.

The only way I've ever seen to kill a catalytic convertor is to run really rich... raw fuel will overheat it, and could cause it to catch fire. (Catalyst heats up when in contact with hydrocarbons, which allows it to separate the molecules to create inert gasses.)

Other than burning oil, I can't think of anything else that would make your NOX that high... unless running advanced killed your plugs.. which is entirely possible, they could have glazed over... you should check that, and do a full tune up, including dry compression test to check for compression loss.

thanks a lot for those tips!

i really didn't drive many miles like that, so, i'll check on the plugs and hope my rings are OK.

if not....well.... i'll have to dig deeper, won't i?

still, great ideas for stuff to look at.

thanks again!