Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: JamesV6CDX on 01 March 2011, 19:14:47

Title: Fault Codes / Lambda issues
Post by: JamesV6CDX on 01 March 2011, 19:14:47
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
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 01 March 2011, 19:16:02
Just to add, performance and economy seem fine

(27 mpg mixed driving - and it flies!)
Title: Re: Fault Codes / Lambda issues
Post by: Jimbob on 01 March 2011, 19:18:00
If your using "My Naff Code Reader", try setting it to 2001 not 2002 and try again :y
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 01 March 2011, 19:22:05
Quote
If your using "My Naff Code Reader", try setting it to 2001 not 2002 and try again :y

Cheers James - I'll pop out and do it again, and repost :) :y
Title: Re: Fault Codes / Lambda issues
Post by: Jimbob on 01 March 2011, 19:24:39
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
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 01 March 2011, 19:34:05
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?  :y

Cheers again :)

Title: Re: Fault Codes / Lambda issues
Post by: RobG on 01 March 2011, 19:35:38
Quote
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?  :y

Cheers again :)

Yep
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 01 March 2011, 19:36:59
Cheers Rob. Much obliged!
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:01:23
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
Title: Re: Fault Codes / Lambda issues
Post by: Marks DTM Calib on 02 March 2011, 19:04:51
Quote
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)
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:10:59
Quote
Quote
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?
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:15:37
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?
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:27:02
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)

Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:37:36
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?
Title: Re: Fault Codes / Lambda issues
Post by: TheBoy on 02 March 2011, 19:48:10
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.
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:50:23
Quote
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.

Hi Jaime

The original code was for S2 - as per first couple of posts :)

It only went to S1, when I swapped the connections as a test, to try and prove/eliminate the sensor... .



Title: Re: Fault Codes / Lambda issues
Post by: TheBoy on 02 March 2011, 19:55:04
So where did I dream you have a P0150 then....


...I'll go back to my Glenfiddich I think....
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 19:56:46
Prefer Glenmorangie... :)

In that case TB, my original fault is with sensor 2

Are values from sensor 2 used in the calculating of the mixture etc? Or is this more of an annoyance than a fault?

Title: Re: Fault Codes / Lambda issues
Post by: TheBoy on 02 March 2011, 19:58:57
S2, AFAIK, is only used for cat monitoring.

Use a meter and check the resistance of the heater circuit. Kevin Wood will know the value - he is a secret lamda junkie  :-X
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 02 March 2011, 20:01:05
Quote
S2, AFAIK, is only used for cat monitoring.

Use a meter and check the resistance of the heater circuit. Kevin Wood will know the value - he is a secret lamda junkie  :-X

Cheers TB, much appreciated :y
Title: Re: Fault Codes / Lambda issues
Post by: TheBoy on 02 March 2011, 20:04:27
Quote
Kevin Wood will know the value - he is a secret lamda junkie  :-X
Most of us go out on a Friday night, he will study O2 sensors for fun


//Edit: Mind you, last Saturday night...   ...I take my hat of to him and the others...  ...the empties on Sunday morning was very impressive.  I'm surrounded by alcoholics ;D
Title: Re: Fault Codes / Lambda issues
Post by: Lazydocker on 02 March 2011, 22:41:39
Quote
Quote
Kevin Wood will know the value - he is a secret lamda junkie  :-X
Most of us go out on a Friday night, he will study O2 sensors for fun


//Edit: Mind you, last Saturday night...   ...I take my hat of to him and the others...  ...the empties on Sunday morning was very impressive.  I'm surrounded by alcoholics ;D

Not our fault you were being a girl and went to bed early :-X ::) :D

Mind you... I should have done. I was knackered Sunday night after doing the same on Friday too ::) ::)
Title: Re: Fault Codes / Lambda issues
Post by: unlucky mark mv6 on 02 March 2011, 23:02:04
Quote
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
Sorry james,my fault mate,as said,attempted to change it sunday,but couldent budge it >:(,ideally it needs to go on a four poster ramp to get the leverage,and your best bet to remove it is stilsons mate. :y
Title: Re: Fault Codes / Lambda issues
Post by: JamesV6CDX on 03 March 2011, 03:29:05
Quote
Quote
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
Sorry james,my fault mate,as said,attempted to change it sunday,but couldent budge it >:(,ideally it needs to go on a four poster ramp to get the leverage,and your best bet to remove it is stilsons mate. :y

No worries mate, it's not a problem. I'll get the badger out one way or another  ;D
Title: Re: Fault Codes / Lambda issues
Post by: pigtown on 03 March 2011, 12:30:38
I had a lambda sensor problem on by 2.2 and the heater on that was 2 white wires and the good one measures about 5 Ohms.
Title: Re: Fault Codes / Lambda issues
Post by: Kevin Wood on 03 March 2011, 13:00:45
Quote
I had a lambda sensor problem on by 2.2 and the heater on that was 2 white wires and the good one measures about 5 Ohms.

Yep, about 5-10 ohms would be my guess.

Kevin