desperately need help with CA smog.
Hi, I've owned my Jeep for two years now, and as expected I needed to get the smog done. I have an 87 4.2L carter carb. Everything is mostly stock, except I'm running 31's, and swapped in a three core all copper radiator, and new thermostat and water pump, hasn't had any overheating issues since. Everything else that I have done shouldn't affect the fuel/ emissions. I took it in the smog shop a little over a month ago after I sent in my registration fee. It failed the 15 and 25 mph test. My hc's were about twice the allowed amount, and my carbon monoxide was 7.2% the allowed amount is around 0.6%. The smog guy took my money and tolled me that it was probably the carburetor running too rich. So I did some research and confirmed that high CO usually means that the engine is running too rich. So I spent the weekend rebuilding the carburetor. I cleaned all the parts, and resembled the carb. And replaced the vacuum choke courtesy of my friend Dennis. I got the carb back on the engine, and fired up the Jeep and then adjusted the idle mix screws. In addition I replaced the fuel pump and fuel filter. The air filter is still new. I took it back to a different smog shop so they could do a pre test. With everything that I did and with some help from the second smog guy (some fine adjustment on the carb), we got the idle CO levels down to about 4.2%. Still eight times the allowed amount. I read some info on how the fuel system works, and came across a thread discussing the O2 sensor. I read that it sends out a voltage between O and 1 volts. A low voltage means it's a lean condition, and a higher voltage means rich. The form suggested to check the voltage on the sensor. The idea is that if you know you are running rich, your sensor should be sending a higher voltage so the computer can lean the mixture. However if you know you are rich, but you read a low voltage on the O2 sensor then the sensor is bad, however I went to test the voltage on my sensor and it read 0.96V at idle and dropped to 0.82V at cruising rpm. From my understanding, this means that the sensor is working properly because I'm still running rich. At this point I don't know what else I could check, our what I can do to pass smog. I really need to pass as I commute to school. I don't want to give it up out of state, it's a Jeep thing, and I know all my problems will go away as soon a I do the fuel injection conversion, which I am planning on doing once I have enough money saved up, and the time to actually do the conversion, Until then I need to pass the ca smog. Any advice or suggestions would be much appreciated. Thanks, chris.