Here's the latest... Changed out spark plugs, replaced with Bosch Platinum +4's and replaced pre-cat O2 sensors with Walker Products replacements. Drove the car about 1/3 mile to local Chevron station, filled it up with 91 octane and added a can of SeaFoam to the gas tank. Car ran smoothly getting there. Left the station and pushed it up to around 60 and before I got back home, stopped at a light and noticed that it was idling roughly and below it's normal idling RPM's. Just as I was making the final turn into my street, CEL came on. Damn! Pulled it into the garage, pulled out my Peake tool and read several O2 sensor adaptation and control limit and cylinder misfire codes. I'm thinking if these were the wrong O2 sensors I would have noticed something right away. I triple checked the part number to make sure these were the correct replacements. Is there some re-adaptation that needs to take place when you change out O2 sensors that may cause error codes before that happens? Cleared the codes and re-started the car and it ran smoothly and no CEL. Didn't run it on the street though. Any hints?