V8 P0134 code O2 sensor

[danpotts24]

Hi to all, first time asking on here, though you guys all seem pretty clever so thought I would give it a go. Have just read the code P0134 sensor circuit bank 1 sensor 1 from the diagnostics. Reset it and the car drove for about 20 miles before returning. I've worked out Bank 1 is the drivers side, is this code for pre or post cat, is it likely to be a dodgy sensor (fingers crossed) or a dying cat (hopefully not!!)

Any help much appreciated

Cheers

Dan

[mike_sekinger]

Hi Dan,

PO134 relates to the RH bank pre-cat sensor.

Would indicate the o2 sensor itself and not the CAT.

Given that all of the o2 sensors are identical - if you have access, maybe you could swap over the pre- and post-cat sensors (including wring connections) to establish if one sensor is faulty.

Cheers,

Mike S

Edited August 1, 2008 by mike_sekinger

[danpotts24]

Hi Mike

My god that was a quick response, I have only just worked out where the answer to my post was, here I was thinking that nobody was going to reply, then I see you only took 11 minutes!! The advise is much appreciated I will order one new sensor a try it at the weekend (if it ever stops raining here in the Lake District!!)

Once again many thanks, will let you know how it goes by next week

Cheers

Dan

[Daniel]

I think Mike was suggesting that you swap the sensor with another (there are 4), and if the fault follows the sensor, then you know it's the sensor at fault.

It may not be the sensor, as the leads tend to get stretched when the car is worked on, especially during things like clutch changes.

[danpotts24]

Hi Dan

Thanks for comments, I realised Mike suggested switching them though though I would just cut to the chase with replacing the sensor, though as you guys reckon it best to switch them over I will give this a go first, I have a OBD 11 reader arriving ( I had to use a garage last time) so will be able to check if it gives a new code. Out of curisoity does anyone know what code it would give for a fault when replaced to the post cat position (presuming it is the sensor of course)

Cheers again for the info

Dan

[kyliesmith.com]

From service manual:

PO134 - RH bank, pre catalyst sensor-

PO140 - Circuit No Activity Detected - RH bank, post catalyst sensor

PO154 - LH bank, pre catalyst sensor

PO160 - LH bank, post catalyst sensor

Description: Rationality check, to see if the sensor is active (a non active sensor shows 0.5v nominal)

[danpotts24]

Thanks for that, Which leads do you check across to check nominal voltage? do you know what page of the manual these codes are on, as I have just bourght the copy of the manual on CD (for V8 and S4), though I seemingly can only find the listing of codes against the 2.2

I know these are pretty stupid questions though I am only just getting into this tinjering myself thing

Thanks again to all that of helped, I had not appreciated how efficient and knowledgable these forums are!

[Daniel]

The reader will give you the voltages, the ones which connect to the laptop certainly do, I assume the hand held devices do too.

I have faulty sensors reading 0.47v constantly, an operating sensor will fluctuate much lower than that.

Incidentally Dan, where abouts in the lakes are you? You're not a million miles from me (Burnley) if you want to bob over and hook up to my PC.

[danpotts24]

Hi Dan

I am actually up in the north lakes nr Keswick, I have just received a Geniscan GS400, which should give readings, though typically the unit can not be recognised by the car for some reason..AAAaahhhhhh!!

[peter_england99]

Dan,

Have you set the protocol to ISO?

Regards,

Peter.

[danpotts24]

Ermmmm....I am sure to most educated people that makes sense......I am not one of the so well educated...how do i do this?

Oh just checking on my reader it automatically scnas through all protocols including ISO though still does not register for some reason

[peter_england99]

Dan,

Do you have the car key in the ignition and turned to position 'II' (Ignition auxiliaries) with or without the engine running? I think this powers up the ECU so it can communicate with the OBDII scanner.

Edited August 5, 2008 by peter_england99

[Günter]

or go the other way, and check that your scanner does not only "scan" all protocols but also does have the necessary contacts for your car in the right place. I think there is an general description in the OBD-2 page...

As i only use an laptop-interface with the additional software , i can't say what settings your handheld scanner does need.

Edited August 5, 2008 by G

[danpotts24]

Hi guys

I have tried all combinations of ignition in position 2 with immobiliser clicked on, also with engine running, both times the backlight comes on so it is receiving power from the plug, but thats it. I have checked the pins also and although the reader does have more pind it does have the corresponding pins 4,5,7 and 16. I fear it may be a case of returning this unit and going back to the garage with a Snap On unit which read the codes fine last week

[Günter]

was there an manual with other setting instructions: like 'time-out mode' , 'clear twin data sheets', 'Anvers: all', 'answering computers/filters: all' nd so on ??

Or if you not interested in further home work , just try to change the unit -and get your money back. For an simple fault code that is an 10min garage job you should not need to study computing skills... . So try the local garage/ car electronic shop!

Edited August 5, 2008 by G

[danpotts24]

Just tp update, replaced the Oxygen sensor, and had the diagnostic read by a snap on unit at a garage instead of my handheld unit, and all seems to be cured...for now!! Thanks for all your help on this one

[kyliesmith.com]

Hi I purchased the EZscan4000 as described on LEW, its pretty good for a hand held unit and gives live data from the 02 sensors and other particulars. I can hook up most of the time. Only twice its failed to make a connection but on the whole very reliable unit I can so far recommend.