Unknown Problem

[scott1212]

Hi ive been getting an engine management light for 3 weeks now. I get error code po155 oxygen sensor/heater circuit bank 2 sensor 1. I replaced the oxygen sensor and fault is still registering. I purged the cat by driving the car for 15 mins between 3000 and 5000 revs and it had no effect. I have repeatedly reset the system and just cant get anywhere with it.Everyone on here has been very helpful and given me lots of good advice but unfortunately the problem persists.Any further help would be appreciated. Thanks.Scott.

[Gooli]

Does your car have the 1AZ-FSE 2.0 litre direct injected petrol engine?

If so, bank 2 sensor 1 should be the the upper sensor on the right side of the engine when sitting in the car, upper sensor on the left side of the engine when standing in front of the car.

You say you've changed the sensor on the passenger side, and if the car is right hand drive (as in the UK), to me it seems you've changed the wrong sensor.

[scott1212]

its a 1.8 vvti petrol.I was told by several people that bank 2 sensor 1was the passenger side thats why i changed that sensor.You seem to know a bit more detailed info so i thank you for your advice and i,ll def look into the other sensor.Thanks for the information.Scott.

[Bibsta]

Hi ive been getting an engine management light for 3 weeks now. I get error code po155 oxygen sensor/heater circuit bank 2 sensor 1. I replaced the oxygen sensor and fault is still registering. I purged the cat by driving the car for 15 mins between 3000 and 5000 revs and it had no effect. I have repeatedly reset the system and just cant get anywhere with it.Everyone on here has been very helpful and given me lots of good advice but unfortunately the problem persists.Any further help would be appreciated. Thanks.Scott.

Hate to say this - but I had exactly the same problem with my Rav4. The engine management light (eml) came on, bit alarmed as the handbook said go to dealer immediately! They diagnosed faulty oxygen sensor (top nearside) bank 1/ sensor 1 (eml test advised code p1135 a/f sensor heater circuit bank 1 sensor 1). Cost to replace at main dealer was circa £250. They told me it wasn't urgent item so I left it - but after awhile thought it best to get it done. However, bought the part £177 + VAT and dealer couldn't remove the sensor from the cat without possible damage (only like removing a spark plug - but it was ceased in) However, my brother is a car mechanic with his own car repair workshop business and he managed to get this sensor out and fitted the one bought from Toyota. He has a diagnostic unit, this showed that the replaced sensor was OK, but next one bank 1/ sensor 2 was faulty (top row/offside - crankshaft) This was replaced at same time - sensor bought from another supplier, original equipment for third of the price? Light went out but after a couple of miles came back on. Another diagnosis revealed that the two bottom sensors were faulty. Following week my brother got Denso (as original Toyota part) sensors, fitted them both and hey presto light went out for good. All told it cost me £500 but could have cost double that at the main dealer. Hope this doesn't upset you, but I was very worried about this problem because I was getting the Rav4 ready for sale and didn't want to spend too much on it. I know this might not be what you want to hear but this was my story! Look twice at cost of oxygen sensors - genuine Denso units can be bought for a third of the Toyota part. John

[Gooli]

If your engine is the 1.8 vvt-i, I guess they are right. Should be on the passenger side.

Just in case, you could test all the oxygen sensors just by disconnecting the connectors and test them with an ohmmeter.

These should be the right type of sensors for your engine. Identify them by the shape of their connectors :

[scott1212]

Thanks for your advice and time guys.Thanks.Scott.

[Legionaru']

Have replaced the oxygen sensor which is number one in the engine compartment.

I think you have changed the sensor under the car!