Sensors & Fault Codes

[wardmj]

I have an 02 2L Toyota Avensis. The engine indicator is on.

I have read the codes using a laptop and the fault code is:

PO141 O2 Sensor Heater Circuit.

I have looked at the readings and they are(running idle):

O2 Sensor 2 Bank 1: 0.525V

O2 Sensor 2 Bank 2: 0.740V

readings are at idel - car appears to run perfectly.

Has anyone had this problem and can advise on best course of action.

[t-spiritpete]

I have an 02 2L Toyota Avensis. The engine indicator is on.

I have read the codes using a laptop and the fault code is:

PO141 O2 Sensor Heater Circuit.

I have looked at the readings and they are(running idle):

O2 Sensor 2 Bank 1: 0.525V

O2 Sensor 2 Bank 2: 0.740V

readings are at idel - car appears to run perfectly.

Has anyone had this problem and can advise on best course of action.

Hi Mate these are not my words but are from MATT BLACK on this forum last year ...quoting his words ....

I- had fault code P0141 come up recently as well. Borrowed a mates OBD reader to read and reset the light, but it came back on a week later.

Toyota wanted a staggering £153.26 for the part. I found an alternative one for £78 from www.autobits.co.uk, fitted it and - touch wood - no problems since. In fact, I would say the car seems much smoother to drive, especially under acceleration. However, I think you should get it fixed, because if the O2 sensors aren't working correctly, it's possible that the car could be running too rich/lean and the maniverter (CATs) could be damaged?

Still, I'm a bit concerned why, after taking the car to Toyota, the light comes on shortly later? It makes me wonder if they're changing the right sensor??

Eg. My code was P0141 - Bank 1, Sensor 2 heater circuit failure. Location wise, that's pretty poor, but you would have thought Toyota would know where it is. Since I didn't, I checked the resistance of the heater circuit at the plugs beside the engine. Check across the black wires only, the blue and white wires are the signal wires. Three out of four sensors were 15ohm (+/- 1) the other was 3.5kOhm. It turned out to be the lower nearside sensor, 950mm long. P/N:89465-20760. The fault light didn't clear immediatly after I replaced it. Since I didn't have my mates reader to hand, I disconnected the negative lead for 10mins, then all was good. Hope that helps a bit. Makes you wonder if the garage just - "assumes" which sensor to replace, replaces it, clears the fault, then shortly later it's back again, because the fault is still present.

Regards Pete.

[Q.S.]

I have an 02 2L Toyota Avensis. The engine indicator is on.

I have read the codes using a laptop and the fault code is:

PO141 O2 Sensor Heater Circuit.

I have looked at the readings and they are(running idle):

O2 Sensor 2 Bank 1: 0.525V

O2 Sensor 2 Bank 2: 0.740V

readings are at idel - car appears to run perfectly.

Has anyone had this problem and can advise on best course of action.

The readings you are looking at are signal voltages I believe. The fault is in the heater circuit.

t-spiritpete's post tells you how to check the heater circuits with a just a multimeter.

[Beagh1958]

To any interested parties,

Just in defence of Toyota for once. They do not guess, they have high end diagnostics equipment to test all parts of a particular model. Your code is a generic code known to all car manufacturers & just as a general rule, bank 1 is sensor before cat & bank 2 is oxygen sensor after cat. This can become more complicated with other cars that may have 2 or more sensors. It would appear you have fixed car to your satisfaction, just one problem , disconnecting Battery does not clear error code it will still be stored in cars ECM. To clear code properly you have to plug it into diagnostics equipment & wipe the memory, then take car for r/test & re check to see if code has registered again in memory, if it is clear your problem should have beem solved.

I would agree with you as to price of component ( all manufacturers charge series money for this component ) as pointed out in above posting you have many companies making these sensors, so you can avoid the high cost charged by Toyota for this component.

Regards, Beagh.