Lambda probe failure?

[knytha]

Hi All,

 

I'm looking for an advice on my Skoda Fabia failed emission problem. It's a 2004 Skoda Fabia Combi 1.2 Classic, Engine no: AZQ517707.

It failed NCT test (Irish MOT equivalent) on CO emissions and Lambda sensor on High Idle (please refer to the pic attached). My mechanic tested it after the test and said it's a faulty Lambda sensor (pre-cat one)  and he reckons new sensor should do the trick and car will be up to the spec again. I checked my local part supplier where I get all my parts and he said Lambda sensors is something they stopped supplying because it's nearly always wrong and only main dealer would get me correct one. Main Skoda dealer is looking for 204 Euro for it.

My questions are:

- do you think changing the sensor will sort the emissions out,

- is it that difficult to buy the correct sensor online rather that from the Skoda dealer as they seem to be much cheaper.

 

Thank you in advance for your help.

[Breezy_Pete]

I believe the correct part number for your car is currently 1K0998262H. New genuine one on ebay here for £90: http://www.ebay.co.uk/itm/VW-Audi-T5-Golf-polo-Touran-A8-Lambda-Probe-1K0998262H-New-genuine-VW-part-/171559498156?pt=LH_DefaultDomain_3&hash=item27f1be31ac

 

Not sure whether their free postage will extend to Eire? I've found this seller very pro-actively helpful in checking that the part is correct for your car prior to despatch.

 

 

My source of information about part number is this page.

 

I honestly don't know for sure that changing this sensor will fix your problem; how many miles has the engine done? Do you have to top up the oil much? Engine wear tends to lead to oil burning, which tends to clog up lambda sensors and catalytic converters.

 

Does it drive OK?

[Alexandru]

I'd say to test the lambda probe before replacing it. Usually, it is the pre heating system which fails at the 1.4 mpi models, but once the engine is heated up and, they do run in the specified parameters. Check the catalyst as well. 

[knytha]

I believe the correct part number for your car is currently 1K0998262H. New genuine one on ebay here for £90: http://www.ebay.co.uk/itm/VW-Audi-T5-Golf-polo-Touran-A8-Lambda-Probe-1K0998262H-New-genuine-VW-part-/171559498156?pt=LH_DefaultDomain_3&hash=item27f1be31ac

 

I honestly don't know for sure that changing this sensor will fix your problem; how many miles has the engine done? Do you have to top up the oil much? Engine wear tends to lead to oil burning, which tends to clog up lambda sensors and catalytic converters.

 

Does it drive OK?

Thanks Wino for your reply.

That sensor theoretically looks fine, but mechanic said it's a 6 pole sensor and this only looks 5 pole. So i guess Skoda dealer is the safest option.

 

Regarding the oil consumpion, I just checked the last cert and the car did 18k miles over the last 12 month, and over that period I used about 15 ltr of oil for topping up as advised by the mechanic who said engine with so many miles would consume more oil. At the moment the clock is showing nearly 162k miles, which is a lot, I suppose.

 

Re the driving I've never had problems with it, but looking back now few times it lost power when driving / accelerating for a split second. Maybe it has something to do with that.

All and all it would be a pity if I had to get rid of this car, because it's been a great car that served me well for the last 5 years. Perhaps it's been abused couple of times too many too. 

 

I'd say to test the lambda probe before replacing it. Usually, it is the pre heating system which fails at the 1.4 mpi models, but once the engine is heated up and, they do run in the specified parameters. Check the catalyst as well. 

 

Thanks Alexandru, that's what I'll do, I'll get the garage to check the sensor as well as the catalyst and see what will come up.

BTW this is a 1.2 HTP 64HP engine rather than 1.4

[Breezy_Pete]

I'm pretty confident that is the same sensor that a Skoda dealer would sell you (where do you see 5-pole?). Phone the ebay seller to confirm. They're a legit company and will tell you if it's not the right item for your car.

I guess you mean 1.5 litres of oil, not 15!?

[rum4mo]

I'm pretty confident that is the same sensor that a Skoda dealer would sell you (where do you see 5-pole?). Phone the ebay seller to confirm. They're a legit company and will tell you if it's not the right item for your car.

I guess you mean 1.5 litres of oil, not 15!?

 

As above, that seller, like many others, bid for and buy up excess VAG stock, stock from folding dealers and stock that has become "not suitable" for sale due to VAG changing its packaging style - none of which should bother us.

 

I tend to agree with your usual parts supplier as VAG tend to use only NTK band of Lambda sensors, parts places will tend to stock Bosch and others. I stuck with buying from a local VAG dealer because when including postage, the saving was very little when buying a NTK same item from an on-line dealer. In your case, it looks like VAG is pulling your trousers down, so buying on-line is best.

[Steve Neate]

Are there any codes on the ecu?

 

SN

[rum4mo]

Are there any codes on the ecu?

 

SN

 

To the OP, in other words, get a full scan done and see it that gives any clues to what is not right.

[knytha]

I guess you mean 1.5 litres of oil, not 15!?

 

15 liters is right. Looking back at it I should've checked this long time ago as it started tu use much more oil after last NCT test (may 2014).

[knytha]

Are there any codes on the ecu?

 

SN

 

Steve, I'll get to my mechanic Saturday morning and get him to do the scan. My girlfriend went there last Tuesday and he said to her it's the lambda probe but I didn't see any piece of paper with the errors he had found. 

As suggested earlier I also get him to check the catalyst to get the full picture.

[Alexandru]

Are there any codes on the ecu?

 

SN

My ECU was pretty vague ragarding lambda probe issues, it was saying about something wrong in the circuit. So I had the circuit tested, retested, the connectors cleaned and so, and after about 2 years, it started saying about heating system. I also ran the VCDS tests for the two lambda probes and the catalyst, and suprisingly, it said the first probe was running fine, same as the catalyst but the very last one was found as being faulty. I wouldn't really solve this issue only by reading the fault codes.

Edited 22 May, 2015 by Alexandru

[Breezy_Pete]

I think at that rate of oil usage, and odo reading, the OP should consider getting a compression test done as a guide to the general health of the engine mechanicals.

Unless I were to take a gamble on a short term patch of fitting secondhand cat and pre-cat lambda, if it were my car Id be thinking head refurb (assuming OK compression figures), or swapping in a low-mileage engine.

[Alexandru]

Right, but in 18.000miles if the owner 

 

Regarding the oil consumpion, I just checked the last cert and the car did 18k miles over the last 12 month, and over that period I used about 15 ltr of oil for topping up as advised by the mechanic who said engine with so many miles would consume more oil. At the moment the clock is showing nearly 162k miles, which is a lot, I suppose.

 

What type of oil has been used ? In that 18k miles, did the car receive an oil change ? Oil consumption depends on a lot of factors, but a compression test is a must in this case. I'd say, without seeing the car, so I might be wrong, that it ran with a too low viscosity oil, that wasn't changed at the correct milage and it burned it. 

[knytha]

Hi Lads, I owe you explanation on my Skoda emission situation.

 

I got the new lambda sensor fitted, emissions tested, and car passed the NCT test today with all the values within the range. It cost me 205 Euro, the sensor plus work, so I suppose it wasn't bad after all. 

@Wino @Alexandru re the oil consumpiot, my mechanic said the faulty sensor caused higher oil consumption. I'll have to monitor that, and see how much oil did it use after 1000 kilometers. I'll wait with the compression test until I know how much oil it actually uses.

 

Just one more thing - on the day the car was going to my mechanic for the lambda change, the fuel pump failed, which cost me another 180E :( I suppose it's time to put aside some spare cash and buy something newer next year.

 

Thanks for all your replies and suggestions. 

[Alexandru]

Just keep the fuel level over 1/4 of your tank and your fuel pump should be just fine. Buying a different/newer car will not guarantee you everlasting reliability. Just ... keep this in mind. All in all, MK1 Fabia is pretty cheap to run and maintain. The O2 sensor is supposed to work about 100.000miles and after this it's recommended to have it replaced.

[Breezy_Pete]

Glad you got it through the test, and hope your mechanic is right with his oil use theory. :sun: