EGT sensor lifespan

[spen]

How often do you have to replace the EGT sensors?

Yesterday I launched the car, and it felt dead on it's feet. At least 100 bhp down. I caught a view of the exhaust and it was a sooty cloud in black. So it was running mega rich or it was failing to fire - the plugs are 10k old now.

I stopped and plugged my laptop in and pulled the DTCs - EGT2 short to ground.

The thing is over the last 18 months I've replaced 3 EGT sensors. Each time it's the electronics that die, measuring the N type thermocouple via an opamp shows that the thermocouple is still ok.

Is this a common failure or am I just 'lucky'? If it's the latter I'm going to relocate the EGT sensor electronics to somewhere cooler as they get pretty hot. I'm also going to try RS6 EGT sensors, subject to getting the ECU adjusted to accomodate.

Any other ideas why this is happening or what I can do to prevent it?

[yorkie]

Unless your maf is on its way out which will kill the egts I would just clear the code and see what happens.

I changed a "faulty" one about a year ago and every so often it dips out with the same fault code despite fitting a brand new maf too.

The fact that it is "short to ground" rather than "implausible signal" would suggest an intermittent connection fault which is what I suspect mine is caused by.

"short to ground" so I'm told by an Audi Master Tech just means that the signal between the egt and the ecu is lost - excactly what would happen if it did short to ground but also if the connection was lost due to a bad connection.

I'm now of the opinion that there was nothing wrong with the egt I replaced and the fault lies in the wiring.

[spen]

maf is ok, still getting 364 g/s.

I think I'm going to clean the connector based on what you said. Cheers.

[mrgristle]

Thought I would resurrect this thread as I am getting the same error code on an EGT sensor I replaced a few months ago. The problem seemed to go away for a while but is now back again. I am suspicious of the way that the cable gets bent through 180 degrees right next to the connector which plugs into the EGT electronics box. It seems to me that the conductors in the cable might be being stressed quite hard. Did either of you manage to fix this permanently? I am thinking that I might cut out that section and re-solder it to the plug. What are your thoughts?

[yorkie]

I never did get to the root of this. I tried re-routing the cable and even insulating it where I found it touched the hose clip for the N75 valve but the problem remained intermittent. For instance last Summer I drove over 1000 miles in France, checked the car before I went and all was ok, checked it again when I got home - still ok. A week later the fault was back but once cleared stayed that way. I wonder if fuel quality may be the problem although I always used V Power when I could get it.

[stapo69]

I've peplaced a lambda 3 times now on mine within about 6 months. Keep getting short to ground fault, is this in the sensor itself? Or could it be something else? Getting sick of it now as its the pain in the arse passenger side one. Or am I just "lucky" too?!