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[JamesV6CDX]

Hi all,

The emissions light (I think it is, anyway) is on, on my 3.2

I cleared the codes earlier, and went for a drive.

About 30 miles later it's come back on.

I've read the codes, and I've got:


P0141 - <Unknown DTC>
 (04) - Intermittent

P0141 - <Unknown DTC>
 (08) - Present

P0136 - <Unknown DTC>
 (04) - Present


The sensors have been moved to get around the precat issue, as recommended.

Which sensors do the above relate to?

Any info gratefully recieved

Many thanks
James

[JamesV6CDX]

Just to add, performance and economy seem fine

(27 mpg mixed driving - and it flies!)

[Jimbob]

If your using "My Naff Code Reader", try setting it to 2001 not 2002 and try again

[JamesV6CDX]

If your using "My Naff Code Reader", try setting it to 2001 not 2002 and try again

Cheers James - I'll pop out and do it again, and repost

[Jimbob]

np, another "My Naff Code Reader" oddity that shows on the later omega's

should then fill in the text more accurately

if not, codes are here

http://www.omegaowners.com/forum/YaBB.pl?num=1220619696

but those arent the usual 420/430 codes the relocating the lambda's sorts

[JamesV6CDX]

Yep, you're right about the "My Naff Code Reader"

The descriptive list of codes is here:

P0141 - O2 Sensor Heater Circuit Open (Bank 1 Sensor 2)
 (04) - Not present

P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
 (08) - Present

P0136 - O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
 (04) - Present


So all relating to that one sensor. (Mark did kindly give me a spare known good one, to help me troubleshoot this )

So - either duff lambda, or a wiring fault!

I looked a live data - while all the other lambdas are cycling, this one is not, it stays at around 4.6v

I guess checking connections, and then swapping out the post cat lambda on bank one, are the first steps?

Without wanting to sound dumb, bank one is the 1-3-5 bank right? 

Cheers again

[RobG]

Yep, you're right about the "My Naff Code Reader"

The descriptive list of codes is here:

P0141 - O2 Sensor Heater Circuit Open (Bank 1 Sensor 2)
 (04) - Not present

P0141 - O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)
 (08) - Present

P0136 - O2 Sensor Circuit No Activity Detected (Bank 1 Sensor 2)
 (04) - Present


So all relating to that one sensor. (Mark did kindly give me a spare known good one, to help me troubleshoot this )

So - either duff lambda, or a wiring fault!

I looked a live data - while all the other lambdas are cycling, this one is not, it stays at around 4.6v

I guess checking connections, and then swapping out the post cat lambda on bank one, are the first steps?

Without wanting to sound dumb, bank one is the 1-3-5 bank right? 

Cheers again

Yep

[JamesV6CDX]

Cheers Rob. Much obliged!

[JamesV6CDX]

Had a look under the car tonight. I was going to remove the offending sensor, but upon looking at it, it's fairly badly rounded off.

What would be the favourite method to extract this?

Also... to try and eliminate the problem, I swapped the connections between the front and rear lambdas on this bank & cleared the codes - and the fault codes coming back are for sensor 1 now - so I'm guessing this pretty much proves it's the sensor at fault?

Cheers
James

[Marks DTM Calib]

Had a look under the car tonight. I was going to remove the offending sensor, but upon looking at it, it's fairly badly rounded off.

What would be the favourite method to extract this?

Also... to try and eliminate the problem, I swapped the connections between the front and rear lambdas on this bank & cleared the codes - and the fault codes coming back are for sensor 1 now - so I'm guessing this pretty much proves it's the sensor at fault?

Cheers
James

Yep....I assume the faulty sensor is a relocated one? (given its a post cat fault)

[JamesV6CDX]

Had a look under the car tonight. I was going to remove the offending sensor, but upon looking at it, it's fairly badly rounded off.

What would be the favourite method to extract this?

Also... to try and eliminate the problem, I swapped the connections between the front and rear lambdas on this bank & cleared the codes - and the fault codes coming back are for sensor 1 now - so I'm guessing this pretty much proves it's the sensor at fault?

Cheers
James

Yep....I assume the faulty sensor is a relocated one? (given its a post cat fault)

I'm not sure actually Mark - as I've never owned a 3.2 and don't know the usual lambda layout on them?

[JamesV6CDX]

Having checked, Mark - my cats are the very  ones pictured in the maintenance guide!

http://www.omegaowners.com/forum/YaBB.pl?num=1253462747

Does this help?

[JamesV6CDX]

Ok, so looking at the pics I can tell I have

One sensor before the precat

A blanking plug between the two cats

A sensor behind the main cat (which is the relocated one)

[JamesV6CDX]

Right - I think I've worked this out in my head.

The FIRST lambda - EG, the one nearest the manifolds - this is the main lambda sensor. EG, the one that provides info for the mixture/fuelling.

This is sensor 1, correct (?)

The SECOND lamda (usually the one AFTER the precat, but BEFORE the main cat) is the one that measures the efficiency of the pre-cats (logical, as it's located directly after the precat, on unmolested models).

This one, is sensor 2 (?)

So my original fault code, at the top of this thread (bank 1 sensor 2) - actually related to the Pre-cat efficiency sensor (the one that has been relocated behind the main cat, to fool the ECU)


Question then. Does having a non-operational / faulty sensor behind the precat (or main cat, on relocated models) actually have any impact on performance and economy

Or, will it just log a code to moan it's not working, however everything will continue to work fine?

I'd heard somewhere it actually uses values from all 4 sensors to adjust fuelling?

[TheBoy]

S1 is before precat, S2 is post starting cat (and main cat for relocated ones).

Your code is a S1 code, thus nothing to do with relocation  :-/

0420/0430 are the codes for the post starting cat sensors.