Are cheap lambda sensors worth a shot? Pre-cat

[Skezza]

So, partners car just went through the MOT. Everything wasn't plain sailing though and although it did pass on emissions (after a bit of welding and a very hard thrash), after clearing the codes and taking it for a drive, my OBD2 Scanner is saying there are two pending faults, Fuel Trim P1070 and P0131 which is 02 Sensor Low Voltage. These were not being triggered before the exhaust was welded, so I'm trying to encourage her to to take for another hard thrash.... perhaps you can regen a lambda? I assume the extra soot is what kills them and I'm sure I've read in the past that lambda's contain small hot wires that can theoretically burn off crap??? Or is that just crap itself?

Anyway, neither are triggering an MIL, but I'm wondering if it's worth replacing the pre-cat lambda nonetheless. I've replaced the coil pack, plugs, etc all that, so I feel like the car is close to being a full bill of health (till the next time).

http://www.peugeotforums.com/forums/eng ... es-223066/

This thread talks about replacing the lambda to fix the potential issues I'm describing. To be honest, I can't really afford £80 or whatever right now Just had a whole load of money fly out of my hands....

Firstly, how do you know the difference between the pre-cat sensor and the post-cat? They fundamentally seem to be the same?

http://www.ebay.co.uk/itm/OXYGEN-LAMBDA ... Sw0kNXhIr8

These guys are offering a lambda for £24 with a years warranty.....? Has anyone tried them? Do they actually work?

http://www.ebay.co.uk/itm/Pre-CAT-Lambd ... xyVLNS5YkR

These guys are offering one too, and claim that it's definitely the pre-cat one? My only issue with the second, is I can't tell how many wires there are? There should be four right?

There's also removing the old one and cleaning it with a wire brush and white spirit, but i have genuinely no idea if that even works.....

Anyway, some help would be great,
cheers

[gazza82]

Difference in post and pre is the length of the cable ... which is part of the lambda circuit so don't just put two of the same on .. I think you will find one has a pale green plug and the other pale blue to identify them.

I'd strongly recommend going with a BOSCH lambda ... I had an NTK on a different car and it wasn't right. Found out later the resistance of the NTK was half the correct sensor. That screwed my MPG ... putting on a Bosch gave me 5-6 MPG MORE!! (and stopped the false error codes!)

You can get a universal lambda which is around £50. Check the Bosch website, but you will probably find the sensor is the same as many other cars .. Alfa, Audi, BMW, Porsche, Vauxhall, etc .. the difference is the cable and connector. They don't need soldering ... they actually warn you NOT to ... but you do need to cut the cable carefully at the right length. I put this on my Alfa to replace the NTK and it was a massive improvement .. no more false codes, etc. And nearly 4 years later it was functioning as new. I would hazard a guess it is the LS615 kit. I got mine from a Vauxhall spares outlet!!


As for cleaning .. if it's a circuitry issue (heater failed, etc) cleaning is a waste of time.


But try an "Italian Tune-up" to start with .. if nothing else it's fun!! You do need to rev a 16V engine to get the best out of it!!

[gazza82]

Universal Lambda Kit and some shots of install in progress ..

lambda_connectorkit.JPG

lambda_connectorseals.JPG

lambda_connector.JPG

red tie wrap was to hold wires in right place .. removed after ...

[Capncol]

Agree re: Bosch.
If money is tight, and it's not actually giving a problem, why not leave it?

[Skezza]

Difference in post and pre is the length of the cable ... which is part of the lambda circuit so don't just put two of the same on .. I think you will find one has a pale green plug and the other pale blue to identify them.

I'd strongly recommend going with a BOSCH lambda ... I had an NTK on a different car and it wasn't right. Found out later the resistance of the NTK was half the correct sensor. That screwed my MPG ... putting on a Bosch gave me 5-6 MPG MORE!! (and stopped the false error codes!)

You can get a universal lambda which is around £50. Check the Bosch website, but you will probably find the sensor is the same as many other cars .. Alfa, Audi, BMW, Porsche, Vauxhall, etc .. the difference is the cable and connector. They don't need soldering ... they actually warn you NOT to ... but you do need to cut the cable carefully at the right length. I put this on my Alfa to replace the NTK and it was a massive improvement .. no more false codes, etc. And nearly 4 years later it was functioning as new. I would hazard a guess it is the LS615 kit. I got mine from a Vauxhall spares outlet!!


As for cleaning .. if it's a circuitry issue (heater failed, etc) cleaning is a waste of time.


But try an "Italian Tune-up" to start with .. if nothing else it's fun!! You do need to rev a 16V engine to get the best out of it!!

Wow, thanks for the explanation. Yeah, I'm going take it for another hard run. We ran it at 70mph in 3rd (about 5000 revs?). It was absolutely screaming, and my missus really wasn't keen, but I think she now understands how important it is, seeing as pre-thrash it not only failed the lambda reading, it also failed the carbon monoxide reading. The garage told her very few cars with both failed lambda readings and carbon monoxide readings can be fixed with an Italian tuneup and it usually requires a new cat and decent money. I, away from the garage, explained to her that while there was a blow in the exhaust, there was no way it would have passed as it's almost certainly running rich and we just needed it welded before jumping to any conclusions.

A quick weld, and a 30 minute screamer thrash, and it passed. Shows how important a proper thrash + a fully working exhaust system is. Unless you're on a diesel of course

Agree re: Bosch.
If money is tight, and it's not actually giving a problem, why not leave it?

I probably will, at least for a few weeks. Let's see if it can regen itself. I want to convince her to take it for a thrash every few days. She drives it fast, but she doesn't necessarily thrash it, if you get me. Hopefully I can convince her. I'll stay away from the cheapo lambdas for the time being. There's a temptation to be a crash test dummy, but for some reason, I have a feeling it won't end well, and me being back to square one in a few weeks.

[iooiuk]

My pre MOT always involves a blast to ensure that the engine is hot when it arrives, but also to clear the pipes


Also remind her indoors, to make sure engine is up to temp before attempting the "Italian Tune Up"

[Skezza]

Good news. Half decent thrash and both pending faults have gone

Result.