After drining the car for about 30mins or so at 60mph to 65mph the car will miss fire or chug ( kinda lose power for a moment ) and then the fans will kick on, and then the service engine soon light comes on, even though the temp gauge reads normal ( just above the line above the 160 mark)
Does anyone know what the problem could be?

 

In certain situations, with certain fault codes, the fans will come on and run when the SES light comes on. It's a safety net for what the computer determines is a poor running engine due to whatever caused the fault.