Rough idle/misfire when cold ???
I'm having an issue with my '85 Thunderbird 3.8. It was having some surging issues when driving around town. I bought a code reader and ran it through both KOEO and KOER tests, and it showed that the O2 sensors were bad. I replaced both of them and the surging stopped. However, it has developed a new problem.
Now it runs rough, stumbles upon acceleration, and misfires, but only when the engine is cold. Once it warms up, everything is great. It drives like a new car. The code reader shows that everything is fine. I'm at a loss.
1985 Thunderbird - 3.8L, C5