On the highway at higher speeds the car starts to sputter then the ses light which is on already starts to flash, but if you let of the gas then ease the gas once again you are able to accelerate. Only seems to sputter when you try to accelerate quickly? Head gasket has recently been replaced.220000

Sputtering is usually a sign of having a fuel issue. You need to hook a fuel pressure gauge to the fuel rail and confirm that you have at least 40# of pressure at the rail.

code p0320 refers to cam shaft position (CKP) sensor/engine speed (RPM) sensor--circuit malfunction=== causes --wiring--CKP/RPM sensor ---ECM
because the engine runs ok until it is on cruise control I would be investigating the RPM sensor for a fault
The cruise control takes its control from the RPM sensor and if that circuit is interminable the the cruise control doesn't know what rpms to maintain.

Find your nearest autozone or auto parts store most will put there scanner on your car for free .they will retreve the code and will than have an idea what part or parts your car needs if this was helpful please leave me good feedback.

The PO 316 is still misfires om first 1000 revolutions
so the shop did a poor job for you on resolveing the
cylinder misfires

Try a diffferent shop

Have to clean the MAF Sensor & replace upstream
oxygen sensors if over 100,000 miles

Need the correct oem spark spark plugs/any brand

No reason the gas filter should be clogged unless it was in
the car for 10 years

Fuel pressure should be checked

Need to check for cylinder misfires on a road test of 20
miles or more with professional software in Mode#06

is there a rattle under the car like the cat converter is bad when was the fuel filter last replaced

I would continue to drive the car. when the light goes out, it means that has corrected itself. The manufacturers put computers in car that will run different models and some times they will throw codes that don't relate to your car. clearing them willsometimes take care of the problem. If the problems continues then have it looked at. If it happens in the future let me know and I can help you threw it.

check for corrosion on the sparkplug wires, both ends. Crankshaft position sensor, cam position sensor and lastly, gulp, the ignition control module..

Have you had it scanned to see what code is in the ecm for the check engine light?

If it was a stock rebuild the original PCM settings should be fine check all the fuses and wiring possibly something was damaged or left loose this stuff happens to the best of us.next the SES light needs to be reset with a scan tool make sure to record all codes stored in the computer as this will aid in diagnosing any problems. the car must be ran thru a drive cycle usually normal driving conditions of say a mix of city and highway driving until the PCM relearns all parameters like o2 sensors emissions sensors ect... this can also be checked with the scan tool in the readiness moniters these monitors will be reset every time the SES light is reset. when pumping the gas pedal 3 time you are just resetting the maintenance light.

Sounds like plug wires.