1996 Honda Accord

Engine Performance problem
1996 Honda Accord 4 cyl Manual

my car is making like a putt-putt noise and is blowing alot of smoke out of my exhaust when I start it up. When I give gas and go it doesn't have as much power as it should. It has some hesitation. Recently I had a new cooling system installed and an oil change as well as new valve cover gasket. The mechanic told me I had oil leaking into where my spark plugs go so thats why he replaced the gasket and the ones surrounding where the spark plugs go. He cleaned off my wires because they had oil on them as well. Do you think my car is doing this because I didn't replace the spark plugs and wires? Also, even though I had a new radiator and thermostat and o-ring installed, my temperature guage still is going to the overheating zone. What could be the cause of this. The mechanic told me he put the car on a machine that told him my engine is not getting too hot. It goes up to 219 degrees and my fans kick on just fine but he doesnt know why the guage still reads like its overheating.