Anti Pollution Warning and Limp Mode Advice

atrixblue.-MFR-.

A lambda sensor and cat issues are symptoms of another fault failed to be diagnosed in my 17 year experience with engines I am self taught so im always learning, ive had allot of help from my BIL who built performance cars and engines himself by absorbing his knowledge i may not all be text accurate in terminology, but in 17 years I have never known lambda and cat issues to fail of their own accord, unless the part was baught new and faulty manufacturing occured.


Lambda sensors mainly fail due to exposure to raw heavy carbon build up on the sensing probe in the exhaust degrading the probe due to over fuelling and excess heat.


the exhaust heating up is due to the catalytic converter trapping heavy carbon deposits and unable to burn it off it then gets blocked up, excess raw fuel/oil (unspent fuels or oil) will also degrade the honeycombe structure inside the cat and cause it to break up inside the exhaust, due to partial blockage back pressure and overheating, it over heats the lambda sensor also damaging it.


both these faults are symptoms of another underlying fault in the chain of events.


If like what I said, a crank sensor is reading faulty, then the engine is disrupted in its operation to work effectively, A crank sensor senses the rotational speed of the engine plus some other parameters such a Top Dead Center or TDC the ECU calculates the rotational speed and converts the rotational speed to aid in ignition timing on every cylinder, if there a disruption in this signal due to faulty crank sensor, the ignition becomes !!!!!!, but fuel is still added as normal, thus a poor out of sync ignition timing with normal fuel flow results in unburnt fuel this then gets into the exhaust system via heavy black carbon paticles being pushed out the exhaust valves down the exhaust manifold into the cat and covering the lambda, the black heavy carbon will degrade the cat converter, the lambda then become heavily soot coated causing excess thermal heating to the probe end, the lambda reads wrong values in the exhaust and thus the lambda tells the ECU this, the ECU then either throws up a fault code for the lambda sensor being out of value's the ECU cant understand and the lambda also plays a part of electronic fuel system and regulating it's output if that cant do it effectively the fuel system gets its fuel air and co2 output value wrong and either adds more fuel into the system or adds less fuel depending on values from MAP CRANK CAM MAF sensors.


this garage is curing symptoms because they are too reliant on a machine to tell the what the issue the ECU knows in wrong. A faulty lambda wont cause stalling issues or hesitation long crank off the key when engine is cold, that symptom is a timing, ignition and fueling symptom, before a lambda fails and makes it worse.

ChellyD86

Thanks for all your replies.

He fitted a new sensor yesterday, showed me the previous one which was all burnt out. He said he took it for a drive and also left it running when he came back to see if light came on or engine cut off but neither of them did.

I got car last night, seemed fine driving home. However, I then had to go out about an hour later and as soon as I put engine on the warning light came back on !! It also slowed down and felt as though it wasn't moving when I was pressing on accelerator. I turned engine off and back on again and it was fine. This morning drove into work again with light on, again drove a wee bit then at a junction turned engine off and back on again and it ran fine. Will be going back to him.

I am now questioning why the ECU was fitted in the first place. This is a friend of my partner's garage not a dealer but obv not convinced he knows what he's doing either. I've now paid nearly £400 and clearly the fault is still there.

BeenThroughItAll

ChellyD86 wrote: »

Thanks for all your replies.

He fitted a new sensor yesterday, showed me the previous one which was all burnt out. He said he took it for a drive and also left it running when he came back to see if light came on or engine cut off but neither of them did.

I got car last night, seemed fine driving home. However, I then had to go out about an hour later and as soon as I put engine on the warning light came back on !! It also slowed down and felt as though it wasn't moving when I was pressing on accelerator. I turned engine off and back on again and it was fine. This morning drove into work again with light on, again drove a wee bit then at a junction turned engine off and back on again and it ran fine. Will be going back to him.

I am now questioning why the ECU was fitted in the first place. This is a friend of my partner's garage not a dealer but obv not convinced he knows what he's doing either. I've now paid nearly £400 and clearly the fault is still there.

What EXACTLY did he fit? I suspect he's fitted a Lambda sensor, which *would* look 'all burnt out' since it fits into the hot exhaust pipe. The one he fitted yesterday will look the same by now I'll wager.


Take it back and insist on the crank sensor replacement as suggested, certainly sounds like that's more likely to be the issue, and it's a lot cheaper than just randomly chucking parts at the car until it's fixed.


In future, I'd suggest finding a better garage.

ChellyD86

BeenThroughItAll wrote: »

What EXACTLY did he fit? I suspect he's fitted a Lambda sensor, which *would* look 'all burnt out' since it fits into the hot exhaust pipe. The one he fitted yesterday will look the same by now I'll wager.


Take it back and insist on the crank sensor replacement as suggested, certainly sounds like that's more likely to be the issue, and it's a lot cheaper than just randomly chucking parts at the car until it's fixed.


In future, I'd suggest finding a better garage.

He said it was a sensor he was fitting. He showed me where he was fitting it into, it was going into the cat in the engine? I'm thinking of going to someone else, just means possibly even more money being paid out but then I'd be doing that anyway!

Thanks again!

colino

Sorry OP, but even your first post highlighted a tech well out of their depth. Unless he is using the cheapest code reader, a fault that threw on the warning light should have easily been traced. Some simple checks could have checked the voltage switching on the lambda and the pre and post cat temps would tell if the cat was working at all. You may well have a couple of faults, but a tech who changes an ecu and a lambda with very little diagnosis probably didn't do even basic servicing checks.
The posts concerning the crankshaft sensor are probably correct, but you need the car checked over by someone who knows what they are talking about and your money back from the enthusiastic, but clueless, amateur.

BeenThroughItAll

ChellyD86 wrote: »

He said it was a sensor he was fitting. He showed me where he was fitting it into, it was going into the cat in the engine? I'm thinking of going to someone else, just means possibly even more money being paid out but then I'd be doing that anyway!

Thanks again!

So it is the Lambda sensor then. The old one looking burnt doesn't necessarily in any way relate to it being faulty. Once a brand new one's been exposed to the 700degC you'll find in the environment in which they work, it'll look pretty burnt pretty quickly.


Clearly the bloke you've been taking it to doesn't have a clue what he's doing. Time to find an alternative and then claim what you can back from the first muppet.


I would demand your original ECU back from him too - although I suspect by now it will have 'gone to the scrapman' or 'gone in the bin', if it were ever actually replaced, that is.

ChellyD86

Aww I could honestly cry !! Over £400 paid out and still no further forward.

Will speak to him again about money back and just take it to someone else who can actually fit it.

I'm guessing I should stay clear of Peugeot themselves as they'll probably charge double before they even do any work?

tedted

i would take it to Peugeot as there was a software update for these vehicles which was for poor tick over and lack of power.they will be able to check whether your ecu is up to date.

atrixblue.-MFR-.

OP your putting too much faith in this "friend" of your partners!.
He's just making money from diagnosis and swapping out parts from what a cheap hand held is telling him, and even I could say the fault code reader wont link up to the ECU its the ECU at fault as im locked out when infact its just my equipment not being of quality! and someone not suspecting and trusting will believe it.


OP in this case my knowledge of the engine 1.4 and 1.6 16v unit is telling me you crank shaft position sensor is faulty, the symptoms are typical of this, and the faults in the ECU are typical of this RE-lambda sensor bank 1 (this all a cheap hand held will give in description and freeze frame values will not be specific enough to interpret to anything meaningful). he is now charging you £80.00 for a lambda sensor that can be baught as a universal one for £10.00 and covert the wires for the conector or £46.00 for a bosch one or £58.00 for direct fit NGK one.


http://www.eurocarparts.com/ecp/c/Peugeot_207_1.4_2007/p/car-parts/engine-parts/fuel-and-engine-management/engine-management-sensor/?419545017&1&e9a28fb5d59d8117a1e82184f44148660bc164e8&000440
as you can see he charging you to cure a symptom for 2-3 months rather than cure the issue completely and cure it for 3-4 years. had you just went ahead and told him change this one first, it would have been cheaper.


what I would have done, multimeter tested the crank sensor had it thrown up abnormal voltages is changed the crank sensor and took out your lambda, I would cleaned your lambda up to rid the heavy carbon, I would have topped your fuel system up with wynns injector cleaner, which will also clean up the cylinders and remove the soot some what, and also took out your spark plugs and replaced them also as they will be caked up in black carbon, reset the ECU EML light and advised you to take it for a decent long run, any issues come back and i'll interrogate the ECU from that point on.
not change the ECU then when that fails change the lambda when that fails change the crank because I would just be bleeding your purse dry.

ChellyD86

atrixblue.-MFR-. wrote: »

OP your putting too much faith in this "friend" of your partners!.
He's just making money from diagnosis and swapping out parts from what a cheap hand held is telling him, and even I could say the fault code reader wont link up to the ECU its the ECU at fault as im locked out when infact its just my equipment not being of quality! and someone not suspecting and trusting will believe it.


OP in this case my knowledge of the engine 1.4 and 1.6 16v unit is telling me you crank shaft position sensor is faulty, the symptoms are typical of this, and the faults in the ECU are typical of this RE-lambda sensor bank 1 (this all a cheap hand held will give in description and freeze frame values will not be specific enough to interpret to anything meaningful). he is now charging you £80.00 for a lambda sensor that can be baught as a universal one for £10.00 and covert the wires for the conector or £46.00 for a bosch one or £58.00 for direct fit NGK one.


http://www.eurocarparts.com/ecp/c/Peugeot_207_1.4_2007/p/car-parts/engine-parts/fuel-and-engine-management/engine-management-sensor/?419545017&1&e9a28fb5d59d8117a1e82184f44148660bc164e8&000440
as you can see he charging you to cure a symptom for 2-3 months rather than cure the issue completely and cure it for 3-4 years. had you just went ahead and told him change this one first, it would have been cheaper.


what I would have done, multimeter tested the crank sensor had it thrown up abnormal voltages is changed the crank sensor and took out your lambda, I would cleaned your lambda up to rid the heavy carbon, I would have topped your fuel system up with wynns injector cleaner, which will also clean up the cylinders and remove the soot some what, and also took out your spark plugs and replaced them also as they will be caked up in black carbon, reset the ECU EML light and advised you to take it for a decent long run, any issues come back and i'll interrogate the ECU from that point on.
not change the ECU then when that fails change the lambda when that fails change the crank because I would just be bleeding your purse dry.

Thank you for this! Shame your in Wales otherwise would have the car straight over to you!

He charged me in total £102 and its still not fixed (as you probably knew it wouldn't be) light came on the day after I got it back from garage and the stuttering is back. When I turn engine off and turn back on again it drives fine.

I'm giving up with him and taking it elsewhere, Peugeot might be the best place as least I'll know they'll fix it and can't be paying out much more than I already have?! Other option is another garage I know near mines that is expensive but when car goes there you know its fixed!

Thanks again for all your advice!