Recently I have had quite a bit of work done on my vehicle. The timing belt and water pump changed out along with the serpentine belt and spark plugs, purge valve as well as a new battery. Last week the EGR valve was replaced and almost immediately after that I started getting the flashing and dinging check engine light. It seems to mainly be when idling at a stop light that it will trigger the dinging and flashing notification. I had the code read today and it is P0300 code for misfires. Could this related to just having the EGR valve replaced? Seeing as it was literally just done and then I started having this issue. I just feel like I fix one thing and immediately I have another issue at hand. Both rear window mechanisms snapped last week as well so having them repaired too has been costly. Any help would be greatly appreciated.