My 94 Toyota PU (4-cylinder, 22RE) is having problems passing emissions... High HC and co2 levels, and a sooty tailpipe. Looks like a rich mixture problem. There is no mixture adjustment (dealer only, it's capped with a metal plug).

Fresh oil, filter, air filter, spark plugs, and brand new 02 sensor... wires appear OK and cap and rotor not bad. Dosn't burn oil and running at 107K miles.

I'm thinking bad cold start injector or something to do with the AFM (though it checks out with an ohmmeter). The cat-converter seems ok also.

Any ideas fellas? (and don't tell me to use a bottle of "will-pass" in the gas tank [:D] )

Drive a sheet metal screw part way in and give a good yank with a pair of locking pliars...  It comes right out [}:D]Might not be emmisions legal though...[(:)]

You should play with the timing a bit. I asked about this a while back for a 92 mazda. If you play with the timing enough, (retard I think,) it will lower the emissions, but it will rob you of power for a while. You should also do it when it is colder in the morning.