Engine Warning Light - Oxygen sensor suspected

[A_VW_by_any_other_name]

Hi all,

 

orange engine light came on. Acceleration has been jerky for a while so I suspect it's something to do with the air flow sensor.

 

I have the Haynes Manual but I'm stuffed if I can find any reference to it. Does anyone know the correct name for this sensor in Skoda speak ?

 

Has anyone had this problem ? Parts don't look too expensive so I am thinking of fixing it. Is it a straight forward job. Or should I just give it to the garage ?

 

thank you

[Breezy_Pete]

We will need to know which engine type your Fabia has.

"Oxygen sensor" usually refers to an exhaust (lambda) sensor, but 'air flow sensor' suggests that you're thinking of something in the intake tract. 

It would be best to scan the engine ECU to see why it has put the fault light on, rather than start firing 'the parts cannon' at guessed reasons.

 

[A_VW_by_any_other_name]

Thank you. I've done a bit more research, and it's probably a lambda sensor. I will take it to a garage as I need a correct diagnosis. Will post on here when I find out. Plus the cost 😞

[A_VW_by_any_other_name]

Update. The garage ran the diagnostics and said it's the top lambda sensor attached to the exhaust manifold.

 

Haynes Manual seems to say it's not too difficult to change but these things are never as easy as you think.

 

I will also need a slotted socket.

 

Anyone done this ? any tips ?

 

Thanks

[Breezy_Pete]

17 hours ago, Breezy_Pete said:

We will need to know which engine type your Fabia has

Still.

Why not let the garage do it? Have they quoted?

 

Edited 1 December, 2023 by Breezy_Pete

[sepulchrave]

1 hour ago, A_VW_by_any_other_name said:

Update. The garage ran the diagnostics and said it's the top lambda sensor attached to the exhaust manifold.

 

Haynes Manual seems to say it's not too difficult to change but these things are never as easy as you think.

 

I will also need a slotted socket.

 

Anyone done this ? any tips ?

 

Thanks

 

I've done it many times, the smart move is to cut the lead off the old sensor and to use a conventional deep 22mm socket to remove it but to only use the special slotted socket to refit the new one.

[A_VW_by_any_other_name]

49 minutes ago, sepulchrave said:

 

I've done it many times, the smart move is to cut the lead off the old sensor and to use a conventional deep 22mm socket to remove it but to only use the special slotted socket to refit the new one.

Thanks I will try this. But I'm struggling to remove the plug from the socket. There seem to be clips on both sides of the plug preventing me pulling it out. Looking at a picture of the new plug, I can see I lift a tab on one side but on the other there are two slots than suggest I have to lift it.

 

I can hardly get my hand in there !

[A_VW_by_any_other_name]

This is the plug/socket for the oxygen sensor. Just can't get this b*tch out.

 

Any ideas.

 

Thanks

[A_VW_by_any_other_name]

4 hours ago, Breezy_Pete said:

Still.

Why not let the garage do it? Have they quoted?

 

Sprry, missed this. It's a 1.2 petrol, manual.

[sepulchrave]

Push the plug and socket together to release the tension on the clip momentarily while you press the release tang, then gently wiggle it off.

[Breezy_Pete]

1 hour ago, A_VW_by_any_other_name said:

Sprry, missed this. It's a 1.2 petrol, manual.

Not to worry.

I'll leave you in sepulchrave's capable hands.

[A_VW_by_any_other_name]

Here is a better picture of the plug/socket. I'm sure I have to do something with the area in red. But I've tried lifting/squeezing/pushing/pulling/poking but it won't budge. Obviously there is a method for getting this undone.

 

I can just about get 2 hands in there.

 

Anyone know ?

 

Cheers

Edited 4 December, 2023 by A_VW_by_any_other_name

[Breezy_Pete]

Flat blade screwdriver that's close to the same width as the gap.

Rest it in there, then as sep says, you need to squeeze the two mating halves of the connector together, then twist the screwdriver to lift that clip.

 

The pushing together is because there's a rubber seal in the midst of the connector which is currently causing the latch to be very difficult to disengage, once you compress that seal, the latch can move freely.

 

 

 

 

[Breezy_Pete]

Watch this from about 1:30 (he has a false start before that where he forgets which way the clip moves.

 

[A_VW_by_any_other_name]

Thank you. The vid was very helpful. I got the plug off eventually. But the new lambda sensor plug is the wrong size. See photo.

 

Ordered off ebay using my reg but still got sent the wrong part.

 

Old plug is left. New plug is right, and obviously too big.

 

Any thoughts.

 

Thank you

Edited 14 December, 2023 by A_VW_by_any_other_name

[Breezy_Pete]

Read the part number off the original sensor and use that to cross-reference a correct one.

If you can't see or read it, message me your VIN and I can tell you current correct PN for your car.

 

[A_VW_by_any_other_name]

Thanks Pete. The VIN is TMBBH25J1A3108853

 

Also found a faint number on the old sensor "VWAG 03E 906 262 C 12V"

 

New sensor has no part numbers on it.

Edited 14 December, 2023 by A_VW_by_any_other_name

[A_VW_by_any_other_name]

engine number CGP 044101

[Breezy_Pete]

Yep, current part info says:

pre-cat sensor is 03E 906 262C

after cat one is 03C 906 262

 

Check ebay listings for any genuine new sensors of 03E906262C part number, but watch out for listings that come up as results for that but aren't really that number.

You sometimes get new old stock ones for cheap.

Or buy an aftermarket one that lists that exact part number as one that it replaces.

 

[A_VW_by_any_other_name]

Thanks will do.

[A_VW_by_any_other_name]

Dear all,

it's fixed. It's like driving a new car. I love reving it in 2nd and 3rd.

 

Thanks to everyone who contributed

 

For anyone contemplating this repair, this is my feedback.

 

1.If I did this again it would take 15 minutes.

2.Get the right replacement part number ( stamped on the lambda sensor itself ). I ordered the wrong one first time. Ebay £22

3. You need a 22m slotted socket to get the sensor out. Ebay £7

4.Take the battery out for better access to the plug.

5. wear some tight fitting rubberised gloves to save your knuckles. ( I used gardening gloves )

6. Pull the plug off the metal bracket. It's held by a rubber plug thing. You can push this back on after you have the new sensor.

7.Getting the plug seperated is the real problem. Squeeze hard with your left hand, while pushing a flat-head screwdriver on the tang thing. There's a YT vid on this. Once you have the technique, it's brute force. These were invented by the devil to make you curse out loud.

8.Use some copper anti-seize grease on the thread of the new sensor.

9.Screw in the new sensor before you connect the plug so you don't twist the cable.

10. Secure any slack in the new cable using zip-ties ( mine was longer ) and route it the same way back to the plug.

 

Enjoy driving again.

[dvt3]

Just wanted to add that I had the same problem after a cambelt changeon my 1.4tdi fabia greenline. Vagcom said oxygen sensor but it turned out to be the plug attached to the bracket LH side of engine. The one attached to the engine mount. It had moved and was touching the plastic pipe. Cables had shorted out and car was revving at 1200rpm. Glad I didnt have to change the sensor as its not easy. Only access is from the top LH side.