my 86 toyota pickup 22r with carb wont pass smog. has 86,000 orig miles. first test past the 15mph test. failed the 25mph test with high hydrocarbon. replaced the o2 sensor and now failed 15 and 25mph test. now hydrocarbon and co2 skyrocketed. I assume i need a carb adjustment since this increase with the new sensor. its running rich. How do i correct this rich mixture. Why else would i have high HC and Co2 after installing o2 sensor?

thanks in advance. i appreciate the help