There is a good chance that the Bank 1 Upper sensor is shot but since it is the toughest one to change, you may want to try the other suggestions which are identical to both codes first. Of course, in the off chance that it could be water getting in the connector, you may just want to clear the code and clean or dry the connector before you do anything. If it comes back, then try the rest of the suggestions.
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.
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, etc.)
�· Deteriorating HO2S sensor
P1131 - Lack of HO2S-11 Switch, Indicates Lean When an HO2S sensor indicates lean at the end of a test, the system is trying to correct for an over-lean condition. The code is set when the fuel control system no longer detects switching for a calibrated amount of time.
Electrical:
�· Short to VPWR or VREF in harness or HO2S
�· HO2S circuit shorted to Ground
�· Water in harness connector
�· Open circuit
�· Corrosion or poor mating terminals and wiring
�· Damaged HO2S
�· Damaged PCM (other DTCs should be present)
Fuel System:
�· Excessive fuel pressure (stuck fuel pressure regulator, restricted fuel return lines, etc.)
�· Leaking/contaminated fuel injectors or fuel pressure regulator
�· Low fuel pressure or running out of fuel (fuel pump concern, fuel supply line restrictions, low fuel level, etc.)
�· Vapor recovery system (stuck VMV, etc.)
Induction System:
�· MAF contamination
�· Air leaks between MAF and throttle plate
�· PCV system / Other vacuum leaks
�· Improperly seated engine oil dipstick
EGR System:
�· Leaking gasket
�· Stuck EGR valve / Leaking diaphragm or EVR
Base Engine:
�· Oil overfill
�· Incorrect cylinder compression
�· Exhaust leaks before or near the HO2S
�· Secondary air stuck on
http://www.v8sho.com/SHO/TSB0197HO2SServiceTips.htm