Persistent Trouble Code P0125

2002 Toyota Tundra; 4.7Ltr V8, SR5 Access Cab, Rear Wheel drive (4 X 2):
I have a persistent Check engine code of P0125 that keeps coming back even though I have recently changed both of the CATs, all four O2 sensors, the air filter, the serpentine belt, the Electronic Temperature Sensor, and the thermostat. I need to get it to pass inspection for State of Massachusetts next month and I'm told they will not pass it with a check engine light on.

Anyone else have any ideas of what to check or do next??

 

Change spark plugs?

 

Already done that too.

 

It had only the P0125 code for a couple of trys and then the P0155 came up for the B2S1 sensor. So I changed that to a "Genuine Toyota" part and it came back again. This is starting to really piss me off. >.<

 

4.7L V8 VIN - Auto

Trouble Code: P0125 (4.7L V8 VIN - Auto)
Insufficient Coolant Temperature For Closed Loop:

Print this code data
Number of Trips to Set Code: 1

• CCM Details
• MIL Details

Trouble Code Conditions:
California Models DTC P0115 and P0116 not set, engine started, ECT sensor more than 140 degrees F, vehicle driven to a speed of 25-62 mph at an engine speed over 1500 rpm, throttle valve not fully closed, and the PCM detected the A/FS or HO2S signal (internal value) did not change. Federal Models Engine started, ECT sensor more than 140 degrees F, vehicle driven to a speed of 25-62 mph at an engine speed over 1400 rpm, throttle valve not fully closed, and the PCM detected the HO2S-11 input did not exceed 450 mv at least during a test period of 1.5 minutes.

Possible Causes:

• * Check the operation of the thermostat (it may be stuck open)
  
  
• * ECT sensor signal circuit has high resistance
  
  
• * ECT sensor has failed
  
  
• * Inspect for low coolant level or an incorrect coolant mixture
  

 

Trouble Code: P0155 (4.7L V8 VIN - Auto)
Oxygen Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)
Print this code data
Trouble Code Conditions:
When heater operates, heater current exceeds 2 A (2 trip detection logic) Heater current is 0.2 A or less when heater operates with +B > 10.5 V and < 11.5 V (2 trip detection logic) Heater current is 0.25 A or less when heater operates with +B ≥ 11.5 V (2 trip detection logic)

Possible Causes:

• Open or short in heater circuit of heated oxygen sensor
  
  
• Heated oxygen sensor heater
  
  
• ECM
  
  

 

Hope this helps, not sure if you already got it sorted out.

You should join us over at Tundras.com, I would have seen it sooner. I rarely log into TW anymore.

 

Neither the OP, who hasn't been on TW since May 23rd.