I have financed a 2022 Santa Cruz SEL that has a Smartstream 2.5L 4-cylinder GDI & MPI engine. I understand what a GD(irect)I(njector) engine is. But what is an MPI. I did not get a clear understanding of what that is and how it is incorporated with the GDI system. Plus, the vehicle makes a really loud noise at cold start (not exaggerating). The dealership found no codes or alert sensors indicating that anything is "mechanically wrong" with the Santa Cruz. It was in the shop for three weeks and no improvement on the sound. It, also, has a somewhat 'zinging' sound every now-and-then. So, the first (or first two) starts of the vehicle is very loud and it'll idle down quiet. Is that normal for this engine or was there a lack of concern or skill (on the mechanics end)? Thank you so much