1.2 64ps (2004) O2 Lambda, Major Service.

[alexh]

Hello.

My 1.2 which I think has the 64ps engine, has the engine light on. It has about 130000miles My bluetooth elm327 dongle reports this as error P0130: malfunction of O2 sensor 1 bank 1. There is no signal reported. I am planning to replace the lambda sensor myself to see if this resolves the issue. Going to have a look underneath tonight to see if it is the 4 pin or 5 pin connection. Wondering about bosch vs NTK vs other sensors, given the age of the car it might not do another 130k, so is it worth fitting bosch or NTK or might I sensibly substitute a cheaper denso or HAAS sensor?

Also think the car requires a major service. I do minors myself, replacing the oil and the oil and air filters. How much should this cost and what will they do? I would like timing chain etc checked for wear as don't want something that could wreck the engine to fail. Also wondering about doing gearbox oil too, given the mileage. Are there other things worth checking on these engines?

Any opinions?

 

[RUM4MO]

I understand your logic for thinking about buying a cheaper replacement, but if any of the stories are true, you might find that after a few weeks you are back to having a problem, and if that happens then you really have wasted some money. It does seem that the engine ECU on some of these VAG cars are just too picky about which Lambda sensor types are fitted and as far as I know, VAG use NTK sensors, also when I needed to replace the B1 S1 sensor on my wife's 1.4 BBY engine Polo 2003MY, I checked on line to see what the cost to get it to my door was, then checked up on the price at the local VW dealer, it was so close I just ordered it in via them with the knowledge that it just had to be the correct part and if not they would need to sort it out FOC for me.

One thing to consider if you intend to stay within the VW group "family" - there are good scan tools out there that can decode VW group fault codes, if you had used one of them, it would have given you a closer reason for that failure which in most cases is the heater circuit and that would have maybe made working out if it really was a sensor failure that you have. After that mileage I'd think that it would be "time up" for a B1 S1 Lambda sensor, the one of my wife's Polo 1.4 only lasted about 75K miles I think.

 

[alexh]

Well, we do have five or six vag cars between me and my parents and in laws, so a good argument for getting vagcom. However I would be somewhat loathe to buy another seat due to their attitude to dealing with faults under warranty or with goodwill. Don't want to have a fight every time something goes wrong! Probably change my tune if the in laws offer a family price on the s3 or golf r though.

Thanks for your thoughts on the lambda sensor.

 

[alexh]

Replaced the lambda sensor with a Bosch one but it threw the same error, and a lambda heater circuit code to boot. Thinking the wiring or the ECU now but that's beyond me so think it's time for an auto electrician or garage.

 

[RUM4MO]

Hum, with a heater circuit fault 9 times out of 10, with an old sensor and lost of miles, it means that that sensor has an internal fault.

With a new, but not NTK sensor??????? Maybe check all the relevant fuses just in case a fuse has gone, a fuse that supplies that heater circuit, after that it could be wiring, did the wiring look okay when you replaced that sensor?

Or, you will find that after about 6 engine starts, this (previously stored) fault will get cleared from the dashboard memory - but will remain in the engine ECU memory until you clear it.

 

[alexh]

The wiring leading to the sensor looked OK when I replaced it, but maybe there is a break further up towards the ecu?

To clarify, after replacing and clearing the old code, it subsequently showed P0130 AND P0030 but after clearing them they have not reappeared. However the live data on the elm317 shows there is no voltage reported by sensor 1, but there is by sensor 2. I am thinking that if there is no voltage then there is a broken circuit somewhere.

Better check the fuse as you say.

 

[alexh]

Very confused now. The code has not reappeared but still no voltage reported by my cheap obd2 adapter. Probably need to get proper diagnostic reader on it.

 

[RUM4MO]

I'm guessing that it is still forcing the fault light to come on on the dashboard?

 

[alexh]

No, it's not, that's the odd thing! Maybe it is working but my device can't pick it up. But then why does it report voltage from sensor 2?

 

[alexh]

Well I have put VCDS lite on it and still no codes, and it does report lambda data, although I'm not so clead on what's what in vcds as yet. Maybe there's no problem.

 

[RUM4MO]

This sounds like replacing that Lambda sensor sorted things out!

Success is acceptable you know?

 

[alexh]

Indeed it is, it has just been a little confusing. I really didn't want to ruin the catalytic converter as it might write off the car.

The program 'Piston' (elm327 obd2 android software) and its failure to report the signal from the pre-cat lambda sensor led me to on a bit of a wild goose chase. However, using vcds lite, and another android program 'eobd facile' have helped to reassure me that it is in fact working.

Thanks for your help RUM4MO.