1999 w/Check Engine Light - Codes P0125 and P1133

[edge10]

I've got an '99 with 19k miles (Mothers car not driven much). The check engine light came on with the following codes P0125 Insufficient Temp for closed Loop and Pending Code P1133 A/F sensor Circuit response Bank 1/Sensor 1 . Coolant level is OK and engine comes up to operation temp normally. Anyone know where the sensors are located (the A/F (O2) sensor seems like upstream but is it front or rear bank?). Any info on testing the senors before replacement? In the past I have measured the voltage of the O2 sensors with a DVM between 0.2-0.8V at 2000 rpm. Thanks.

[toyomoho]

P0125 code can deceiving as the problem may have nothing to do with the coolant system. The manual states the code is tripped if the A/F sensor output does not change over 1.5 minutes under defined conditions such as MPH 25-62, throttle not closed, engine RPM 1500 plus, etc.

The P1133 codes relates to a A/F sensor that is slow to respond, Bank 1, Sensor 1. The A/F sensors can become sluggish in response over time.

[Qslim]

Both of these codes relate to the air/fuel ratio sensor, and Bank 1/sensor 1 is in the exhaust manifold closest to the firewall. Keep in mind that the construction of the A/F sensor is different from an oxygen sensor in that you cannot directly measure the voltage output with a DVOM.

[edge10]

Originally Posted by Qslim

Both of these codes relate to the air/fuel ratio sensor, and Bank 1/sensor 1 is in the exhaust manifold closest to the firewall. Keep in mind that the construction of the A/F sensor is different from an oxygen sensor in that you cannot directly measure the voltage output with a DVOM.

Thanks for the info guys. Is this a Wideband or Titania sensor? If can't be measured with a DVM is there another way to confirm it is bad or it is changing out a pretty sure thing based on the codes?