when warm, it smooths out and runs fine, except for slightly reduced fuel economy. O2 sensor has been changed. injectors bench tested ok. ??vacuum leak?
Might be a vacuum leak or something related to the cold start/run circuit. Sometimes the temperature sending units send erratic info when they are wearing out (but not completely failed) and the computer gets "confused' as to whether it is in closed loop (up to engine running temp) or not. Good luck.
