some serious chugging when started in the cold. After a bit I hear a click and it starts running smooth. what to do?

Hello, often time cold start issues can be caused by air intake leaks, meaning the engine is getting too much air for a cold start, resulting in poor running. You could also certainly have a fuel delivery or quality issue, as well as ignition spark. Monitoring the components of the air, fuel, ignition and emissions systems with a high quality diagnostic tool will provide important information to help troubleshoot your concern.