Q: Engine light on, black smoke coming out exhaust on acceleration and fault codes

The glow plug faults are most likely going to cause a hard start condition, which will be most noticeable when the engine is cold. The colder the engine, the more difficult it would be to start usually. Often times, glow plug failures aren’t noticed until it winter time. The relay fault is saying that there is a problem with the ECM relay, likely that the relay is staying on too long, which will need to be diagnosed. As far as your black smoke and bad noises, the underboost fault is the most likely cause of these issues. It could simply be a boost leak, which would cause a rich fuel mixture, resulting in black smoke and low power, or it could be a failing turbocharger, which would result in low power and black smoke as well. These are not the only two possibilities, simply the most likely. To find out for sure, you would need to have a qualified technician, such as one from YourMechanic, come to you and diagnose the check engine light and the smoke from tailpipe, after which they will be able to suggest an appropriate repair.