ray collins: Hello people. Good evening. Pls I need help. My mums toyota camry XLE is guzzling fuel. Well I can't categorically state if it is guzzling fuel or if it is d guage dat is nt working well becos dere was a time dat it showed E on the guage. I opened the fuel pump and had to check the remaining fuel in the tank and it was more dan quarter. Immediately I replaced the fuel pump assembly and cranked the engine the guage qmoved to quarter tank. Anoda issue is dat the multifunction display shows dat my AVG miles per gallon is between 19.5 to 20.+ which is relatively ok for city driving. Rite? Anoda issues is dat my miles dat car can travel keeps reading 0 but I can still drive a whole lot before car finally dies becos of lack of fuel

D dilemma

When we kinda noticed an increase in fuel consumption, I quickly used my scanner to scan the car and it brought out codes P11135 meanin air fuel sensor heater circuit malfunction bank 1 sensor 1.
I checked d code online and saw that it can drastcally increase fuel consumption. I ordered for the original denso aair fuel sensor connected it my self but it didn't workm I have since replaced it like 5 timess up to no avail. Immediately I replace it and crank the engine, the check engine light comes on immediately indicateing d same problem

Benin mechanics

I have been to like 200 different mechanics(just kiddng) but no one seens to know what function d air fuel sensor plays. All of dem keeps sayin oga nor worry e nor mata . E nor dey do any fin. How clueless. I am very handy when it comes to car repairs like I have changed the thermostat my self, replace the coolant temp sensor and even did change my plugs my selp. NB I just replaced the plugs with denso OEM spark plug SKR0211 .

Help.
Pls if anyone can direct me to a good mechanic in benin dat has worked on oxygen or air fuel sensor before I will be grateful or if any one can assist cos I have d beloief dat its nt d air fuel sensor dat is faulty but may be dere is an electrical connection somewhere dat is not rite. U can ask oda questions if u r nt clear HELP A BRODA OUT

Thanks.

ray collins: Waitin

Ikenna351: ray collins,

Stop looking for those clowns to cause more harm for the vehicle. As far as am concerned, you are doing just fine with your diagnosis. All you need is patience, time and guidance.

Now, that the ECU is reporting a fault with the upstream sensor, does not mean the sensor is faulty. Its only telling you something is wrong at that end. Its left for you to find out what actually is the problem. I wouldn't blame you for replacing the upstream sensor the first time, because of the code you got, but I would have tested the sensor when you realised that the fault didn't go away after the replacement. Don't rely so much on what a scan tool tells you.

Since I do not know much about Toyota injection system, I will use Peugeot injection systems to explain what you need to do on this issue.

o2 Heater Power source: Peugeot use Universal oxygen sensor for their injection systems (except few older Peugeot EFI systems). And Bosch brand only. By universal sensor, I mean 4-wire o2 sensor. Now the Bosch oxygen sensor has a heater. The heater has ground and 12v+ wires (2 out of the 4 wires on the sensor). Some of their EFI systems have their o2 heater power source 12v+ from relays, while some are powered directly from the ECU. So, if the heater relay fails, the heater wont get its 12v+, meaning the sensor wont work. So, you need a Digital MultiMeter (DMM) to test that wire with ignition or engine running, to be sure the heater on the sensor is still been powered (still receiving the 12v+ and ground). Whatever you find, will tell you whether to rule out heater power source or fix the power source.

o2 ECU signal wire: Did it occur to you that there could be dis-communication between the o2 and the ECU via the signal wire? You need to check the continuity of that signal wire from the sensor to the ECU wiring connector with DMM. I know two methods of checking continuity with DMM, but its going to take me a lot of time, if not part of the night to explain them. Do you know how to use DMM? Connectors could corrode, hence, ECU would be receiving incomplete or no values from the sensors. Rodents could eat or chop off those wiring harness, 1 or 2 wires, which would lead to loss of signals from the sensors those wires are connected to. So, test the ECU signal wire continuity, including the two ground wires to the o2, assuming yours is 4-wire o2 sensor.

ECU or o2 sensor: The cause. The LH2-2 (Jetronic) of my Baby works like this: The Injection ECU, through the ECU signal wire, sends about 1.5v to the o2 sensor. Then, the Bosch 02, through the same signal wire, sends about 64 millivolts to the Injection ECU. This result can be attained when the signal wire is disconnected in btween the o2 and the Injection ECU (on the o2 connector, if you like). It works like a thermistor (CTS). So the o2 is supposed to reduce the higher values the ECU is sending to it and return a lower value as the system warms and CTS gradually reduce consumption (with the help of heater part of the o2 sensor, though). So, when the two sides of the signal wires are joined together, you should be getting on your DMM about .80v or so, less than what you will get on the ECU side when the signal wire is disconnected. So, am not sure of Toyota, but for my LH2-2 system, anything more than 1v when the 2 wires are connected would mean the sensor is faulty, since its supposed to reduce the values the ECU sends to it and return the reduced value back to ECU. Also, if the ECU fails to send any value to the sensor, even though the sensor is sending the .64 millivolts, then either the ECU is faulty or there is a dis-communication somewhere on the wire. Likewise, if o2 sensor fails to give about 64 millivolts, then its not working. Note that not all DMM have millivolts function.

If you can carry out the above test on the car, you will know if the o2 sensor is the culprit or the ECU, including the wires with which the 2 components communicate with each other, and the heater relay, if any.


If you do not have the wiring diagram/schematics of that car, it's time to get one. Good luck!


Ikenna.

ray collins: @ ikenna yes. Fuel guage goes down so fast, upstream sensor keeps throwing out d CEL illuminated light. I ususlly clear code before replacing but it comes back within 5 seconds. Thanks

Costee: OP the possible causes of your problem are stated as follows:
- Faulty Air-Fuel Ratio (A/F) Sensor Bank 1 Sensor 1
- Air-Fuel Ratio (A/F) Sensor Bank 1 Sensor 1 harness is open or shorted
- Air-Fuel Ratio (A/F) Sensor Bank 1 Sensor 1 circuit poor electrical connection
- Faulty Engine Control Module (ECM)
You have only addressed the first on the list. Other contributors have advised that you look into the other issues. You say you used oem sensor, could you post the part#, and possibly your VIN so we can ascertain you're using the right part for the right car.




@ costee thanks. Yes I've. Only done 1 dat is replacing d sensor. Have nt done 2 3 4 nor 5 cos I don't know how to go about dat. Can u pls explain. Will be very grateful or lemme use our best friend GOOGLE. #smiles#