Lambda issues?

[Andy207cc]

Hi all, I've got fault codes p0135, p0141 (O2 heater circuit both sensors) and p0443, p0444 (purge control valve circuit).
Cars a 2008 207cc. Does anyone know if this is likely just a new lambda required or possibly something more going on?
It just seemed strange to me that both sensors were showing faulty heater circuits and I'm not familiar with the purge valve.

[GiveMeABreak]

Best to pop your VIN up for me so I can relate the faults to the exact engine ECU fitted as these will vary. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

I am out and about today so will get back when I can.

[wheeler]

Unlikely its a faulty oxygen sensor. The power supply to both oxygen sensor heaters & the purge valve (there are a few names for this, I would normally refer to it as a charcoal canister electro valve) they are normally powered from the same supply from the under bonnet fusebox & normally share the same fuse.
Are there any symptoms apart from engine management light?

[Andy207cc]

Thanks for the replies, I'm not with the car today but will get the vin number ASAP. Along with the eml the dash is flashing up depollution system faulty and its idling irratically.

[Andy207cc]

Vin number in case this helps...VF3**************[VIN obfuscated, can be read by forum staff]

[Andy207cc]

It seems the engine is running very rich, the spark plugs were very black and sooty and you can smell petrol from the exhaust fumes.
The same codes keep returning after a code reset and I've tried disconnecting the battery over night too.
The car seems a little sluggish but it seems the main symptom is a very lumpy idle.
I've tested the O2 sensors and they appear to have power and about 0.6 ohms resistance.
Does anyone have any idea where to look next?

[ozvtr]

It seems the engine is running very rich, the spark plugs were very black and sooty and you can smell petrol from the exhaust fumes.

You can not let this continue or you will destroy the catalytic converter and then you will be up for some serious coin! The "aging catalyst" (de-pollution) DTC will be because of the rich mixture.

The car seems a little sluggish but it seems the main symptom is a very lumpy idle.

A rich mixture will do that.

I've tested the O2 sensors and they appear to have power and about 0.6 ohms resistance.

I cant see what engine you have.
Could be a bung upstream O2 sensor but I don't think so. There is more than that going on here.
The heater circuit(s) will not effect the over all performance of the engine at all. They just speed up the time it takes for the O2 sensors to get to operating temp. However the heater DTC may be a symptom of another problem. For one reason or another the engine ECU can not or does not ground out the heater (and I also guess the purge valve) circuit. These are two innocuous circuits, and on the surface should not effect the running of the engine. But again, I think that there is more going on here than meets the eye.
The O2 sensor elements produce their own voltage and do not rely on the supply voltage to form input the engine ECU.
Oh which reminds me, does the engine run any better/worse when cold?
I think this is a fundamental problem like power and/or ground.
Check the engine ground strap.
You are going to have to check ALL the powers AND grounds to the engine ECU before you proceed.
If ALL the powers and grounds check out, it might be the engine ECU. But lets see.

[wheeler]

Vin number in case this helps...VF3**************[VIN obfuscated, can be read by forum staff]

There's a digit missing from the VIN you posted.
OK so there is actually a running problem too not just fault codes relating to the oxygen sensors.
with the engine warmed up & idling what live data readings are you getting from the oxygen sensors? Is it showing its in closed loop?
The upstream should constantly fluctuate between 0.1v - 0.8v. The reading of the downstream sensor is not too important as long as it stays pretty much the same.
As Oz says the heater element is only for getting the sensor up to working temp faster, it shouldn't affect any readings or cause any running problems if it was not working.
You can do a resistance check on the heater elememts, what you should get varies between different brands of sensor, Bosch ones are normally between 8-10 ohms. You measure the heater element resistance across pins 1 & 2 with the sensor unplugged.

[Andy207cc]

Thankyou both for your replies, the live data is showing open loop on the fuel system/ O2 sensors.
Vin...VF3**************[VIN obfuscated, can be read by forum staff]

I've thoroughly cleaned the engine bay and inspected the wiring which all appears in very good condition from what I can see. I've got a second hand ecu coming so I'll see if that makes any difference. I also thought it could be the upstream sensor sending dodgy signals and causing over fuelling possibly.

[Andy207cc]

I should add... In response to ozvtr, I haven't driven the car much but the times I did there didn't seem to be any difference when it was warmed up.
As for the live data my scan tool just says fuel sys fault open loop on the O2 sensors and doesn't give any data for them.
Just to check does the 5/6 pin connector for the upstream O2 sensor use pins 1 and 2 for the heater, I thought it was 3 and 4 but I may be wrong.

[ozvtr]

I should add... In response to ozvtr, I haven't driven the car much but the times I did there didn't seem to be any difference when it was warmed up.

I also thought it could be the upstream sensor sending dodgy signals and causing over fuelling possibly.

I wanted to know if the engine ran better in open loop mode but obviously not. It's possible the O2 sensor is shot and the long term fuel trims are maxed out. That will cause the engine to run rich in both open and closed loop. But in that case there should be a DTC for the O2 sensor not being within a nominal range. But you didn't mention a DTC for the O2 sensor being out of range.....Hmmmm.
I cant see the VIN so I don't know what engine you have. I'm guessing the Prince engine as you said the upstream O2 sensor has a 6 pin connector?
If that's the case your engine runs a wide band O2 sensor and I'm not too familiar with them. They don't "switch" but give an analogue voltage out of between 1 to 3 volts (typically). A voltage output of about 1.5V at 1.0 lambda (or stoichiometric). This voltage can only be read by the engine ECU and displayed on a scan tool. You can't measure it with a multimeter at the plug. I would assume the engine ECU would have an upper and lower voltage output threshold before it threw a DTC (as I said before).
Unfortunately that doesn't explain the 'open circuit' heaters and purge valve. Having said all that, the heaters could be open circuit. It's not beyond the realms of possibility. They are quite fragile. As Wheeler says the heaters and the purge valve usually have the same supply. But one step at a time.
So you either have multiple faults or it's something to do with the engine ECU.
The heater is pins 3 and 4 (the contacts in the middle of the electrical plug) for the upstream and the 2 white wires (on one end of the connector) for the down stream.

You need to get a hold of a circuit diagram and check that all of the supply and grounds for the engine ECU are good.

[ozvtr]

As for the live data my scan tool just says fuel sys fault open loop on the O2 sensors and doesn't give any data for them.

Fuel system fault but no DTC?

Does your scan tool tell you the fuel trims?

[Andy207cc]

I believe the 2 lambda sensors and the the purge valve share a power feed wire so maybe its possible that a fault with 1 of these can throw up all 3 fault codes?
I was wondering if the upstream sensor was faulty too as I've read even a heater circuit fault can cause the ecu to over fuel the engine.
I can't see any fuel trims with the scan tool I have but it says
O2 sensor 1 -0.012mA
Bank 1 sensor 2 0.455v

[Andy207cc]

I've just measured the heater circuit resistance on the pre cat sensor and it's reading about 04.5 then another time it read 06. something.
I checked the pins on the plug coming from the wiring loom and all the pins showed about 3v power and when I checked for ground they all showed about 9v. Im a little confused by this but maybe its normal.

[wheeler]

Just to check does the 5/6 pin connector for the upstream O2 sensor use pins 1 and 2 for the heater, I thought it was 3 and 4 but I may be wrong.

Sorry yes, never realised this was a 6 pin connector. 6 pin ones its pins 3 & 4 for the Heater. On 4 pin sensors its 1 & 2.