C180 cutting out - O2 Sensor??

[dawood83]

Dear all

Hi I have a 2001 C180 Classic auto petrol.

Last night I was driving and after a few miles the engine management light came on, about 5 miles later the car started choking on the motorway,looosing power, cutting out, so i parked on a side street, called AA recovery, the guy put his laptop in and diagnosed the fault and said the O2 Sensors pre-cat and post-cat are gone and need to be replaced. He reset the engine management light, but this was still happening hence he said this was not simply a software issue.

Took it to my mechanic he said they will cost £130 EACH and no point in getting non-merc ones which are much cheaper, they wont work properly. Is that right - cause if htat is right im looking at a £300 bill.

a) Do you think the AA diagnosis was accurate and
b) can i not use non-merc lambda sensors - please help!!
c) Where can I get good cheaper lambda sensors

thanks

Dave

 

[television]

I would have said GSR or Euro car parts, firms like Parts co and Parts service do keep a good range that the trade use.

Do remember that the O2 sensor measures the exhaust gas passing through, if it is too rich, it will try and reduce the fuel air ratio, the tester could have just picked up the fact that this sensor has changed from its stored setting

 

[kth286]

dawwood83

If you have other means of transport then you can relax a while, BECAUSE I just do not believe that two lambda probes/sensors would go all of a sudden and by replacing them the car will again be perfect.

They normally gradually lose their effectiveness.

also the heater circuit inside them can go open circuit, and again they will become inefficient.

BUT something must have caused them to go wrong at the same time, so must be a simple fuse or relay somewhere that is faulty.

Ideally you need to go to a Merc specialist that is familiar with your car and has the latest diagnostic system.

Where you located ? Someone can advise a specialist (not main dealer)

 

[dawood83]

Hi

I live in Leyton, East London. I am just worried that it isnt something big... my local garage is asking for £40 labour to replace those , and each is £130 or so from Merc. very steep.

 

[television]

This is a small run down of both diesel and petrol engines

Symptons.
---------
Difficult to start.
Misfires when starting, then clears
Car starts, then dies
Car will not start at all
-----------------------------------
Causes
-------
Poor or incorrect fuel atomisation
Leaking injectors,air lock
Poor or incorrect fuel delivery
Injector resistance or impedence
Corrosion on injector harness terminals
Blocked catalyser /lambda
Incorrect injector application
------------------------------------
Consequences
--------------
Inlet valve gumming or sticking
Bore wash
Loss of compression
EGR valve gumming
Fuel contamination of oil
Damage to Lambda and Cat
Exhaust valve carboning

 

[miro]

Sounds like the engine harness is full of oil. Much like previous threads.

The clue here is that multiple sensors are going offline.

 

[dawood83]

Hi Symtomps were.

Engine management light came on, after 3 miles, car just lost power, but after 2/3 seconds, power would come back suddenyl and car would speed ahead, also later onwards the car would not change gears ,i.e. driving at 30 mph would be in 1st/2nd gear with rpm constantly sticking at 4000rpm. Then suddenly the car would go powerless and then suddenly pickup and race ahead.

On startup the car did start, but kind of misfired, and had slight vibrations when parked...

There was also a chemical smell when I got home and parked the car. All in all, very worrying!!

 

[mightymouse]

my old pug 406 had the same issues and right now its the second week and a local specialist garage is having a hard time fixing it. he said that the mett or matte (dont know which one) sensor died. but i had exactly the same symptoms as yours. changed the lambda sensors but it didnt help at all. not sure if this is help at all