None 75 problem/petrol engine expert needed?

[Nomis]

I dont have a 75 which is someting I regret since selling but do have a problem.

Any petrol engine experts about?

I have a pug 406 2.2 sri. It is the same 2.2i 160bhp engine which is still used in the 407.

I have a fault which turns the engine management light on. I bought a code reader and it gives 2 faults, both lamda/O2 sensor faults. I replaced the sensor for an NTK one as its done 86k but the same fault comes up not long after clearing with the code reader.

I also have a very jittery uneven idle which makes the car jump around on idle. I put some forte injector cleaner in and also filled the tank with shell VPower.

It runs as fast as it ever has but just lumpy on idle and the fault code.

I was wondering if the NTK sensor is faulty also or it just does not like it ot I have a faulty coil pack or even the map sensor is faulty giving the same code. Another theory is a duff Cat causing the same fault?

It has got me baffled and I would like to sort it and sell it as it may be tricky to sell privately with the current issue.

I have tried on a 406 forum but it is a very quiet place so thought I would try here:lol:

Any pointers apreciated.

[Phil]

They have two 02 sensors don't they? One pre cat and one after cat, are you sure your code relates to the one you've replaced?

[Nomis]

Not sure. I can only see one and when buying it was only listed as having one, a front one.

I could get under again and check but I deffo could only see the one on the front of what looks like the cat or front exhaust?

[T-Cut]

On my 75, the lambda codes were due to the catalyst failing, not the sensors themselves.

TC

[Nomis]

Originally Posted by T-Cut

On my 75, the lambda codes were due to the catalyst failing, not the sensors themselves.

TC

Thats what I was thinking.

[Phil]

If it has two o2 sensors, the second one monitors the performance of the cat, the front one before cat hasn't a clue what the cat is up to, only the rear one can know that. What year is the Peugeot?

[Nomis]

Originally Posted by Phil

If it has two o2 sensors, the second one monitors the performance of the cat, the front one before cat hasn't a clue what the cat is up to, only the rear one can know that.

Just looked again and it seems it does have 2, doh. The one I replaced was thrown too. I need to get the car up and look again.

When I unplug the one I fitted it makes no difference to the lumpy idle either and as I said the fault code returns reallt quickly.

[Phil]

Originally Posted by Nomis

Just looked again and it seems it does have 2, doh. The one I replaced was thrown too. I need to get the car up and look again.

When I unplug the one I fitted it makes no difference to the lumpy idle either and as I said the fault code returns reallt quickly.

What was the exact code, do you remember?

[Nomis]

Originally Posted by Phil

What was the exact code, do you remember?

P0136 - Generic - O2 sensor circuit malfunction
P0141 - Generic - O2 sensor heater circuit malfunction

Both say bank 1 sensor 2

Should have realised from that there are 2 sensors really. I guess I was not looking for another while fitting this one.

[Phil]

Originally Posted by Nomis

P0136 - Generic - O2 sensor circuit malfunction
P0141 - Generic - O2 sensor heater circuit malfunction

Doing a google search on those codes seems to point to sensor 2 aftercat, but I thought only the front one was heated?