Engine Management Light

[N20]

Afew days ago the engine warning light came on I have done all the basic checks and other than air filter which I replaced everything seems to be ok... I reset the Light but and it came back on, but only after I had put another 4-6 miles on the clock... The engine seems to be running just fine, no noticeable change to performance.

As I dont have access to a fault code reader I was thinking of just replacing all the O2/oxygen sensors and see what happens after. Is this a good idea?

I know there are many things that can trigger the CEL/EML but it is a relatively simple job and is not too expensive to change all three.

Was looking at these for the pre cat sensors..

http://cgi.ebay.co.uk/Lambda-Sensor-Toyota-Corolla-Hilux-Land-Cruiser-Prius-/140392768574?cmd=ViewItem&pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item20b00fa43e

[man-bing]

I recently had that problem too with the engine light thing coming on, but i just disconnected the Battery, and it sorted itself out, but sounds like you have a more serious problem then :(

Here's my topic and replies

Malfunction indication lamp

[N20]

Yes it does... As I said I was thinking of changing all the O2 sensors as I belive they are a common cause of the CEL/EML.

Just wanted to know if it was a good idea to change them. the car is nearly 8 and has 68,000 on the clock and i belive the sensors commonly last 60,000 - 100,000.

There is a OBDII reader on eBay for £14.99 maybe i should get that.

http://cgi.ebay.co.uk/U380-OBD2-EOBD-OBD-2-diagnostic-code-Reader-Scanner-/270587523858?cmd=ViewItem&pt=UK_Diagnostic_Tools_Equipment&hash=item3f0045f312

[cfc1]

I would get a code reader, the one you linked to will do the trick (U380), but I don't know if it will just give you the code or whether it will give you the code and tell you what it means.. eg.

Code reader 1. - PO135

Code reader 2. PO135 Heated Oxygen Sensor Circuit - Bank 1 Sensor 1.

Try and get a reader that gives the better info.. I have the U381 which also gives the freeze frame data that triggered the error and also tells you other live info such as fuel trims, O2 sensor voltages etc etc.

Better late than never??

[N20]

True, Better late than never... But I had already ordered that one... It gave me the code P0141 and I believe this to be the O2 sensor/s so I ordered these from eBay

Yesterday I changed both the pre-cat sensors and then today the dammed light came back on. It has the same fault code P0141. So now I am going to have to change the post-cat sensor. can i use the same sensor as i used pre-cat? If not can you please reccomend me one?

Thanks

[cheetah1]

This here: http://www.obd-codes.com/p0141

[cfc1]

P0141 = O2 sensor heater circuit malfunction bank 1 sensor 2.

Bank 2 has 1 sensor (on the manifild)

Bank 1 has 2 sensors (one on the manifold..sensor 1, and one next to the main cat.. sensor 2)

As you would have worked out by now, the two sensors on the manifold which you have already replaced will be perfectly ok, all along it's been the sensor next to the main cat.

The problem with the sensor is the heater, these heat up for a very short time when the engine is cold so that it sends the correct voltage to the ECU, once the engine is warm the sensor itself is hot enough and the heater cuircut isn't needed.

This sensor doesn't interfere with the fueling, so the fault won't cause any problems (other than the CEL), you can fix it with a resistor as described here...

http://www.mr2roc.or...tor+fix#p146489 (worth a read)

Should you deceide on a new sensor (read the link above first) then it's probably cheaper going to http://oxygensensors...680&height=1050 just check exchange rates etc.

Of course, if the wires on your other sensors reach, you can use one of those.. just hope you haven't binned them yet.

[N20]

I have not binned them. I think i will wait until the problem is cured then stick them on eBay.

Typical, I change 2 of 3 sensors and the only one I have not changed is the faulty one At least i will have a shiny new set.

Having looked at that website you told me about I’m not sure if the ones I already got would be long enough... I think what I will do is on Friday when I have more time I will take the cover off the bottom of the car and have a look. I think i would prefer to replace the sensor with a new one.

Thanks for the help

[N20]

I purchased the Walker O2 sensor you gave me the link for (250-24404) but was surprised when parcel force sent me a bill for over £20.00 for customs and what not.

What a cow to install, the old sensor was so dammed tight I’m lucky it didn’t round off and the exhaust was always in the way... Anyway just have to wait and see if it cures the fault.

I now have a new problem with the car... Two kids on a push bike decided to use the side of my car as a brake. Needs a new front wing, aerial and mirror not to mention scratches :( Just hope I can claim off of someone.