Grrrrrrr. Lambda Sensors

[JamesV70R]

Why oh why! I replaced the sensor on Saturday, did about 45 miles since then - all with no light and lovely and smooth - and as I pulled in to Shell at lunch the damn light came on again!!!

Got home and read the codes - 1133 - O2 Sensor Insufficiant Switching (Bank 1 Sensor 1)

Right people, I need thoughts. What can be causing this. Its NOT the Front 02 Sensor - as I say its got 45 miles under its belt and is brand new Bosch.

Am ordering new spark plugs today - wouldnt be surprised if they are fouled, but what else can cause 02 sensors to throw up that fault?

Cheers,

James - Coming to the end of my patience!

[dpbayly]

when the light is on is there any difference in the way it runs?

Only reason i ask is because Ive come across a few cars at work that throw up o2 sensor faults and even on the live data show the o2 sensor not switching but when i looked into it in more detail it turned out to be a faulty air Mass sensor giving false readings which messed the fueling up which in turn messed the O2 readings up.

But the cars also ran badly very flat and hesitant.

[JamesV70R]

Runs a little rougher - slight vibrations through the engine, slight hunting by about 100rpm or so.

Will go for a short drive with OBD2007 on, and have a glance at the data afterwards to see the fuel/air ratios etc. that it has logged.

Will see if I can get the MAF off tonight and take a look inside to see if there is any obvious dirt or damage on/to the filaments.

[dpbayly]

It's not normally obvious to look at it but if it does run slightly off try just unplugging it and running it, it will log another fault but as its unplugged the ECU will use other info from other sensors to sort out the fueling and if the air flow meter was giving readings that were way off it should run better disconnected

[JamesV70R]

Unplugged the MAF - Car started running lumpier so I'm reading into that as MAF is OK - or at least in a workable state even if its not in the best of conditions?

Also, it threw a light on the dash for my ETS, and when I turned the engine off again the cooling fan turned on and wouldn't turn off. Plugged the MAF back in and restarted the car and it eventually stopped. Went for a short drive around the block with OBD2007 Lite logging on the seat next to me (very short drive!) and kept a screenshot of the end of it. Bear in mind I didn't go over 25/30mph the whole time ..

Hope its readable, and maybe helpful to someone in pointing out a problem?

Oh and PID 0x03 - Fuel System - when sat in the drive was switching between Open Loop (System Fault) and Open Loop (Driving) or words to that effect.

[gdphillips]

how old is the cat...............?????

[dpbayly]

Ok sound like the MAF is ok, on your live data screen can you bring up bank1 sensor1 voltage and see if when the engine is up to running temp its switching from between around 0.2 up to 0.8 and switching in a nice regular way every second high low high low.

[Jp003]

Originally Posted by Villan

Why oh why! I replaced the sensor on Saturday, did about 45 miles since then - all with no light and lovely and smooth - and as I pulled in to Shell at lunch the damn light came on again!!!

Got home and read the codes - 1133 - O2 Sensor Insufficiant Switching (Bank 1 Sensor 1)

Right people, I need thoughts. What can be causing this. Its NOT the Front 02 Sensor - as I say its got 45 miles under its belt and is brand new Bosch.

Am ordering new spark plugs today - wouldnt be surprised if they are fouled, but what else can cause 02 sensors to throw up that fault?

Cheers,

James - Coming to the end of my patience!

Hi your fault code does point to the first O2 sensor and could be a wiring fault, multiplug incorrectly connected or HO2S

Doubtfull that the sensor is faulty from factory if Bosch

Did you install correctly?? Check the plug and cable for damage

You can test the sensor with continuity and voltage tester but its a bit fiddly

dissconnect component and test between terminals 3 and 4 usually top and bottom in middle of plug, should get aprox 3 Ohms (heater circuit)

if you have no CAT or old one then this may cause the code to come up but i think code P0141 is more likely as sensor doesnt heat up sufficiently

Also test with ignition on between 3 and earth should get 11-14V at socket end (car end)

Hope this helps?!?!?!? Always seems to be more than one thing that can be wrong with these cars at a time and guessing which one is hard

If you want to eliminate the CAT take to MOT station and do emmissions test and that will show if sensors are working correctly, If O2 level is at about 0.70 then its probably the CAT like my car which recently failed on O2

regards John

[triton2]

We have an 1994 normal aspirated 5cyl 850 that has two problems:

Car may stall at stop lights while idling.

The engine will often not re-start when warm. Will start after sitting for a few minutes.

Lately the car quits while driving on the freeway. Just quits, but will restart after a few minutes.

We cleaned the Throttle Body, Idle Air Valve and Flame Trap. Car has new NKG plugs and runs great, except for the engine quiting problem. We are thinking electrical, even perhaps the ignition switch? Any ideas??

Thanks,
Scott

[Jp003]

Any engine codes coming up?