2007 Dodge charger 2.7L remanufactured engine 1 year old. Cylinder 5 misfiring, engine shakes a bit at start, speedometer dials jump up and down randomly while driving home speed stays constant. (These are only every once in a while)

The engine runs high temp ..(215°f with AC off.. up to 225°f when the AC is on). But the thermostat only goes to the middle never passed (I get the temp reading from my OBD reader through an app) it looks as though it may be leaking something from the air hose?? OBD has no codes currently but will throw code for catalytic converter, and incorrect immobilizer key most often than any others. Other times it had shown codes for EGR valve, misfires, cylinder 5 fuel injector. And sometimes the codes don't come in for a misfure but OBD will show over 400 misfires... There's more but I need help narrowing it down as every mechanic I bring it does nothing and I'm really tight on cash. You know the story... I was thinking fix that leak and have the EGR valve cleaned or replaced first?? Any help in directing me to direct e the mechanic would be greatly appreciated








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