I have a 2006 Freestar SEL 4.2l and no matter what I have done, I cant get the engine light to go away!

It started out of the blue a few months ago. it would idle fine but surge/ hesitate under load. The emissions light came on so my wife went to have the code read. she went to auto zone and the kid told her it was P0304, cylinder 4 misfire. Apparently he must have inspected the plug wires because he said there was a split in the #4 wire.
She brought new wires and plugs home for me to change but the code didnt go away. thankfully I had not yet reassembled the cowl and wiper assembly before running it. the #4 wire did have a small slit in it but the coil pack had a few visible cracks. easy change.
The light was gone for about 5 miles but the van still ran rough. when the light came back, I took it to get read again and there was a new code for the camshaft position sensor. Again I replaced the part that I was told was faulty and again I still have the light on and now a 3rd code.
this time the code is P0133 for the bank 1 sensor 1 O2 sensor.

so with all of that, I have two questions...

1. I have found a lot of conflicting info about the bank 1 sensor 1. I read that bank 1 is ALWAYS on the cylinder 1 side of the engine and as you know, in the Freestar, that is against the firewall. This did not come from one source, many say the same thing.
The guy at Autozone and a local Ford mechanic both tell me that the B1 S1 sensor is the one in front between the engine and radiator.

has anyone else replaced this sensor? can anyone else tell me what source is right?

2. I know, I know that I should never throw parts at a problem but the way I looked at it was... the van has over 80k miles and the parts I replaced were tune-up related parts. Not that an O2 sensor is not routine, but now I am 3 repairs and 3 unique DTC codes in and the symptoms are exactly the same as day 1 when the problem started.

Should I be looking at a not-so-obvious source of my problems?

thank you in advance for any input that can possibly be given on this.

 

Cylinders 1,2,3 are the radiator side of the engine while 4,5,6 are the firewall side of the engine, thus BANK 1 sensor is on the radiator side of the engine.

What make/model plug and wires were used?

Did you apply dielectrical grease to the plugs and both ends of the wires?

The P0133 code is the O2 sensor responding too slow. Before replacing the O2 sensor, I would start with ensuring that the electrical connection is nice and clean. Coat with some dielectrical grease.

 

Sorry guys, but cylinders 1,2,3(Bank1 - HO2S#11) are on the firewall side and 4,5,6 (Bank2 -HO2S#21) are on the radiator side according to the Ford 2004 workshop manuals which i used for ignition cable and O2 sensor replacement in the past successfully.
I found this link a bit late just trying to see how easy it was to access the bank2 sensor1 oxygen sensor and found this.

Also, i would not get any type of silicon dielectric grease on the pins as they will conduct now only over 0.3volts and that would mess up any o2 readings. The pins are gold plated for that reason, hence the cost. The grease should only go lightly and carefully over the outer boot connector seal to keep moisture out much like with the sparkplug cables as mentioned by Common Sense, no offense.

 

when you have a misfire condition the monitors, ie. O2 monitor for one, will not run. Now that you have fixed the misfire the monitors will run and hence the new codes.