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96 Bronco w/ 351 & AT - single exhaust - 107K miles. Have trouble code P0133: O2 Circuit Slow Response (Bank 1, Sensor 1). Does this indicate a failing (old) sensor? If so, should I replace all 3 at the same time? Since the O2 sensors are so critical, are there better sensors than others? (Note: I recently had other O2-related DTCs. I replaced all the hardline vacuum hoses, air cleaner, & cleaned the MAF (as guided by excellent guidance in another post) and the code cleared up.) Thanks to all who care.
 

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Wrenching for a Livin'
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normally, that is an indication of a failing or failed oxygen sensor heater, which would mean its time to replace the mention sensor. I can't recall if the '96s monitored the O2 heaters or not. Sometimes when the heater gets weak you will get the slow response code because it takes the sensor so long to warm up with the weak heater. If the computer monitors the o2 heaters you will get a heater failure code when the heater gets weak or fails.

Either way its likely just the o2 sensor. you can verify it quickly by checking the o2 heater fuse and relay and verifying voltage at the heater pin of the o2 harness with the key on.

Those o2 sensors have a 60k recc. replacement I *think*. They will last much longer than that. Def. replace the bad one. Its good preventative maintenance to do the rest, but not usually required.
 

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They have O2 sensors in 78-79?

Didn't know that! :histerica Just kidding but someone had to say it! May as well be the English A**H***!
 

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yo,
Great info from MAGNUMPI:thumbup

here is what I posted here awhile ago;
DTC P0133 - HO2S Sensor Circuit Slow Response (HO2S-11)
The HO2S monitor checks the HO2S sensor frequency and amplitude. If during testing, the frequency and amplitude were to fall below a calibrated limit, the code will set;

Possible Causes:
Electrical: · Shorted/open wiring ·
PCM Induction System: ·
MAF sensor (On 4-cylinder engines, if P0133 is present, this could be caused by a MAF issue - on 6- and 8-cylinder engines, this could only be a MAF issue if P0133 and P0153 are both present) ·
Inlet air leaks (unmetered air)
Fuel Concerns: · Poor fuel quality Base Engine: ·
Exhaust leaks (upstream or near HO2S)
HO2S Concerns: · Contaminated HO2S sensor (contamination from the use of silicone-based cleaners and sealants, leaded fuel, excessive oil consumption - Deteriorating HO2S sensor; OBD II Response Rate Monitor: The OBD II Response Rate Monitor (P0133/P0153) is only run at vehicle speeds between approximately 50-95 km/h (30-60 mph), during steady-state conditions. The test lasts approximately 6 seconds. Therefore, P0133/P0153 cannot be diagnosed at idle in the repair bay...

Most replace the O2 Sensor; but ck for wiring/connector/harness damage and other likely and no $ parts replacement checks 1st; incl testing the sensor ckt; fuses, heater ckt, etc.

Fords naming convention is that bank one is the same bank as where the number one cylinder is sensor one is before the cat sensor two is after the cat.
Source: by miesk5 at FSB
 
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