Hello! I’m experiencing a few engine & code issues with my blazer. So to give some backstory, today i did quite a bit of driving around, and towards the end of my day i noticed my car was running extremely rough, like at idle my rpms & oil pressure would be sitting lower than usual and the car would be shaking quite a bit and when i went to accelerate the car seemed to want to stall. i did notice turning the ac off and or putting it in park or neutral would help the issue but not completely get rid of it. after a little bit of this i decided to pull over & inspect under the hood. with the hood up i went to shut it off and when i did it made this loud pop like a line somewhere had blown and my buddy said the engine shook like crazy. i looked around quite a bit and started it up and it ran like it was before. afterwards i scanned it with a code reader out of curiosity (last guy took the bulb out so i couldn’t see it throwing an engine light) but sure enough it read a pending and stored p0440 (Evaporative Emission System), a stored p0300 (random/multiple misfire), and another stored one for running too cool (preexisting issue). With this information, what would any of you recommend to do first? Any help appreciated!

 

I suggest fixing the coolant temperature sensor first, reset the codes, drive, see what codes come back.