Hi All I am looking to purchase an extension lead to as per the link below but the cost is £76, this appears expensive, any thoughts?
I have looked for other suppliers but cannot find any!
I considered extending the leads but U tube clips etc give so much conflicting data, including must solder / you must not solder and the length will change the configuration
http://www.racingbeateurope.com/bmazda-mx5-2006-to-2015-racing-beat-manifold-wiring-kitb-1585-p.asp
Any advise would be helpful
Thanks
Derek
I can’t see there being a problem extending the wire yourself, but the joints must be good, the sensor is only producing less than 1volt. I think that the sensor wires are difficult to solder though due to the metal that they are made of. Something I seem to remember from past experience but not 100% sure. I’d be tempted to use non-insulated crimp terminals and block connectors similar to the OE plugs. Demon Tweeks, for example sell water resistant block connectors and terminals. The sensor terminals in the OE plugs are gold to ensure good contact and no corrossion.
something from this range for example
http://www.demon-tweeks.co.uk/motorsport/wiring-connectors/auto-marine-super-seal-connectors
Hi Derek
My idea to replace the lambda with a universal planar sensor and use the connectors supplied would cost a lot less.
Here is the spec…
http://www.fpukfindapart.co.uk/findapart2/cataloguelistpart.asp?Make=MAZDA&Model=MX%2D5&Litre=2.0 Petrol&Engine=LF-DE&oldLitre=2.0&fueltype=Petrol&bodytype=Convertible
Just select oxygen sensor from the parts list and see the last item - post cat universal cross reference.
The benefit of this is bespoke connectors and just the single break
Here is another idea, if you are confident with a soldering iron…
https://www.youtube.com/watch?v=DCFKCZw9vlE
I’m not sure how water tight heatshrink will be and there will be two breaks per wire to join.
If the wire is a high temperature stainless type (for example) and not the usual plated copper then it will not solder easily and instead a good quality crimp is essential. But in most cases soldering and shrink sleeving is best.
If you specify ‘adhesive lined heat-shrink’, that is water tight if it is the correct size to shrink enough to grip the cable without the glue. We used it on the connectors to our underwater cameras at work years ago, none went below about 50 metres but also none leaked.
If the wire is routed close to the exhaust then a type with high temperature insulation should be used, and not the ordinary plastic covered wire.
It makes sense to use the same thickness wire.
Good luck.
Edit.
I notice Robbie mentioned gold contacts. Don’t solder to gold, it works at first, but after a while the tin migrates into the gold (like dissolving) and the joint is dry. At work we had expensive transistors with gold plated legs soldered into some expensive high grade PCBs and after about two years in service they simply fell out! Re-soldering them a couple of times saturated the gold and the problem went away.
The cables of many lambda sensors are stainless steel, rather than copper.
Having tried to solder them, I now know better. The crimps work fine though.
To make heatshrink waterproof, I smear a little clear flexible glue such as “UHU” on the cable outer before shrinking over it.
Caution: Do not use a naked flame near the glue. Use an electric heat gun or a hair drier.
Just a quickie when I fitted my new full system including decat pipe I used the after cat mounting point as it was easier to fit the sensor into than the front one and the cars emissions were through the roof I moved it to the front one and it’s emissions were fine so I did a bit of research and it seems that the sensors only work correctly with hot gasses flowing over them by moving it back that extra distance the gasses cooled and gave false reading also the sensor has to be fitted before a cat not after
Yes, a lambda sensor needs to be at about 600 degrees C to work properly.
They work by “comparing” the difference between the oxygen content of the exhaust gases and atmospheric air on the outside of the pipe.
They produce up to 1 Volt when the difference is greatest.
If the air/fuel ratio is correct (stoichimetric) there should be no oxygen in the exhaust gases. Then the sensor will produce “maximum” voltage.
If the sensor is faulty, or not fully up to temperature, the produced voltage will be low, or zero.
The ECU then incorrectly assumes there is some oxygen in the exhaust gases (weak mixture) and will increase the fuel flow to “use it up”.
So, a faulty Lambda sensor gives poor emissions due to the mixture being incorrectly made too rich.
Btw, the reason your emissions went bad after fitting a decat pipe…
A cat convertor produces a lot of heat (almost red hot inside) so the exhaust gas temperature increases as it passes through - this is what they are designed to do. This will heat the lambda sensor directly behind it very efficiently.
If you remove the cat, that heat source is no longer there. So the sensor won’t be up to temperature at low power or idle.