Have the same year so check the COP Coil on plug. Have replace mine and that what it did , just like yours. It was # 4/5 cops. Took the dealer 4 hours to decided it was breaking down under load. Check the heater hose that runs to the passenger side rear of engine and if see if wet, replace hose and put on a couple feet of wire loom split up and all the way down till touching engine. Now that I know, it is easy to check. There were no codes. Remove the COP and use a spark plug wire and insert between the COP. Then use your old timing light and connect to spark plug wire and watch the light. Drive it and with helper watch the light. It will stop firing if bad. Dealer was watching a frequency meter at $125 an hour.
