1996 Ford Taurus I get a Code P0306 or P0303 and have a CMP

I'm guessing you loosend the synchroniser ? it needs setting @75 degrees .. the actual sensor itself can be removed/loosened without the problems of setting up afterwards ... it could be the sensor itself needs relacing causing the misfire codes .. let me know

Camshaft Position (CMP) Sensor
EEC-V uses 2 types of CMP sensors. A variable reluctance sensor is used.
CMP sensor is used to determine the position of the camshaft and to identify when piston No. 1 is at TDC of compression stroke. CMP sensor provides cylinder identification information during engine start-up for PCM to initiate correct firing order. Cylinder identification information signal is sent from CMP sensor to PCM through CID circuit.

CAMSHAFT POSITION SENSOR
Removal & Installation (OHV)
Disconnect negative battery cable. Unplug harness connector from Camshaft Position (CMP) sensor. Remove CMP sensor mounting screws and sensor. To install, reverse removal procedure. Tighten mounting screws to specification. See TORQUE SPECIFICATIONS . For CMP sensor synchronizer removal and installation procedure, see CMP SYNCHRONIZER .
Removal & Installation (DOHC)
Disconnect negative battery cable. Disconnect CMP sensor harness connector. Remove CMP sensor retaining screw and CMP sensor. See Fig. 5 . Ensure "O" ring is properly located and in good condition. To install, reverse removal procedure. Tighten screws to specification. See TORQUE SPECIFICATIONS .
Fig. 5: Removing CMP Sensor (DOHC)
Courtesy of FORD MOTOR CO.
CMP SYNCHRONIZER
Removal (OHV)
Note position of CMP sensor electrical connector. Remove CMP sensor. See CAMSHAFT POSITION SENSOR . Before removing synchronizer housing, set piston No. 1 to Top Dead Center (TDC).
Apply reference marks on synchronizer housing and engine. Remove synchronizer housing hold-down bolt and clamp. Remove synchronizer assembly with intermediate shaft.
Installation
Install Synchro Positioner (T95T-12200-A) on synchronizer assembly (CMP sensor removed). Turn synchronizer shaft clockwise until tool boss engages with notch in synchronizer housing. Tool should fit squarely in top of synchronizer housing.
Install intermediate shaft in synchronizer assembly. Lubricate synchronizer drive gear with engine oil. Insert synchronizer assembly into engine. While inserting, synchronizer assembly will rotate. When installed, synchro positioner should point 75 degrees from engine centerline. See Fig. 6 .
If synchro positioner is not pointing in correct direction, remove synchronizer assembly and start again from step 1). If installed correctly, install and tighten hold-down clamp and remove synchro positioner.
Install CMP sensor and tighten screws to specification. See TORQUE SPECIFICATIONS . Connect CMP sensor harness connector and negative battery cable.
Fig. 6: Positioning Synchronizer For Installation (OHV)

The codes you are getting are just misfire codes they could be from plugs/wires/coil/CKP/CMP. Generally (but not alway's) the PCM will pick up on a fault from the CMP and give a code from the CMP. I would be double checking my timing before replacing any part's it could be that slight little degree out? Causing the misfire. If you definately feel it is the cam sensor you could just replace it or reset the synchronizer to 75 degrees

I never advised you to change the CMP ... I advised against changing any parts untill you had double checked the timing ? have you checked your timing marks are spot on ? the special tool setup states it needs to be @ 75 degrees from centre line of engine as shown in the diagram

CMP SYNCHRONIZER
Removal (OHV)
Note position of CMP sensor electrical connector. Remove CMP sensor. See CAMSHAFT POSITION SENSOR . Before removing synchronizer housing, set piston No. 1 to Top Dead Center (TDC).
Apply reference marks on synchronizer housing and engine. Remove synchronizer housing hold-down bolt and clamp. Remove synchronizer assembly with intermediate shaft.
Installation
Install Synchro Positioner (T95T-12200-A) on synchronizer assembly (CMP sensor removed). Turn synchronizer shaft clockwise until tool boss engages with notch in synchronizer housing. Tool should fit squarely in top of synchronizer housing.
Install intermediate shaft in synchronizer assembly. Lubricate synchronizer drive gear with engine oil. Insert synchronizer assembly into engine.
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********* While inserting, synchronizer assembly will rotate. When installed, synchro positioner should point 75 degrees from engine centerline. See Fig. 6 .

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If synchro positioner is not pointing in correct direction, remove synchronizer assembly and start again from step 1). If installed correctly, install and tighten hold-down clamp and remove synchro positioner.
Install CMP sensor and tighten screws to specification. See TORQUE SPECIFICATIONS . Connect CMP sensor harness connector and negative battery cable.
Fig. 6: Positioning Synchronizer For Installation (OHV)

You must have had the chain off to remove the heads .. are you sure the timing chain marks are lined up correctly ?

No you don't have to remove the chain? I was asking have you checked the marks? A PO300 code is random multiple misfire. Random as in. ALL or some cylinders in an engine cycle. If you are sure the timing marks for the chain are lined up . Ther next thing you need to do is get the synchronizer back in position? I don't understand how you were getting you 38 degrees reading from the centreline of engine with a ruler?

I will look into the degree's issue in the morning. Send me the pic's when you can . 38 Dg and 75 Dg is a big difference.I'm going to look into why the other manual say's 38.