Rather then replacing again / more ( which depending on the millage, if over 60K all 4 should be done ), the same one ( HO2S-11 ), did you check a few things :

When testing is :

Engine Coolant Temp: 150 to 240 F ?
Vehicle Speed 30 mph to 60 mph ?
Engine RPM 1000 rpm to 2000 rpm ?

The test will not run if there is excessive purge ( check this for blocks ? )

The Possible Causes list :
1. Contaminated HO2S sensor. -> Should not be, replaced.
2. Exhaust leaks. -> Is there ???
3. Shorted /open wiring -> Did you check the wiring after replacement ?
4. Improper fueling. -> Are you buying crap fuel ?
5. MAF sensor. -> Have you checked this to see if it is clean ?
6. Deteriorating HO2S sensor -> Should not be, replaced.
7. Inlet air leaks. -> Have you cleaned / repalced your air filter lately ? Is it correctly put back together ?

There are a few things away from HO2S-11 that can cause the code, considering this is a closed loop test, rather then replacing parts for the heck of it. That said, O2 sensors are not on the scheduled maint list, but by all indications, all 4 should be repalced around 60K or so, just to keep them operating at peak performance.

There is a note under the Diagnostic Aides section :Access HO2S test results from the Generic OBD-II menu to verify DTC. This is what Steve was indicating, that you should have a Ford dealer doing, or at least a really good independant, that is fully equip'd.

 

Found the problem. A wire broke off in the connector on the other side of the sensor. Not the sensor connector, but the mating one it plugs into. Can the connectors be bought seperatly?

 

At Autozone they had quite a few connectors, as does Napa.

With this said, I have not looked for an O2 sensor connector, but I know I saw all other sorts of connector sets.

Maybe try one of those 2 first. ??

 

Checked. No luck. It's going back to the garage tomorrow that replaced the sensor. I guess I will let them deal with it. They never clipped the connector housing back in place. They just let it hung.

 

I replaced all four of them and the MAS AIR flow sencor and I still get this code and last week my truck started to run rough like it was miss fireing and then the service lite came on and then started blinking like crazy and then the engine began working ok but the service lite stayed on I cheched the codes agian and got PO306 for Cylinder 2 & 6, and PO133 O2 sensor circuit slow response BANK 1 sensor 1,

so now have my engine apart and going to change all the fuel injectors to see if this fixes the problem do you have any other ideas???

 

The time to ask such questions is BEFORE you jump off the deep end and take the freakin' thing apart....

It's also not a good idea to resurrect threads buried years ago....

 

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It's also not a good idea to resurrect threads buried years ago....
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what do you mean by this???????????????

 

This thread was created 6yrs ago.