Codes PO 440, PO441,PO446, P1135 on 2001 Toyota Sienna

My Toyota Sienna with 155k displayed codes PO440, PO441,& PO446, I took it to the dealer and was told that the Charcoal Canister could be the problem. This repair would cost about $400+ with labour. Been unable to afford the repairs I continued to drive it until I noticed that the mileage dropped significantly. I checked the codes again and noticed that code P1135 was added to the list, also when starting cold it wont idle until it gets warm. My question; Is the A/F sensor the same as Oxygen Sensor?. Which one is it, and how do I check to see if it is defective. Your advice would be appreciated.

In a nutshell an 02 sensor and an A/F sensor to a parts guy are the smae but they are very different. One is a wide band 02 and the other a conventional 02. To avoid confusion see your toyota dealer to be assured you're getting the correct part and the Charcoal cannister is quite probable for the rest of the codes. Very common failure on alot of Toyota's

P1135 = Air/Fuel Sensor Heater Circuit Response (Bank 1 Sensor 1).

A/F Sensors are similar but different than a O2 sensor...they are not interchangable.

You could Ohm the sensor but it likely needs replacement anyways.

Hi Jeff, Thanks for your response. If both sensors are similar but different, how can one differentiate which is the wide band 02, and conventional 02. To be on the safe side, I will remove it and take it to the dealer, as they would be better able to know which of the sensor is it? and is there any test that can be done on the cannister to determine that it is defective. Again, Appreciated.

Thanks for your reply. Would Sensor 1 at bank 1 be the A/F sensor? If its not, Where would it be? and is there any recognizable difference between it and the 02 sensor.

They will look very similar and be located in the same place on the engine, the exhaust but a vehicle will have one or the other not both if that's what you're asking. The dealer parts guy should be able to get you everything you need