What's this wire? Got cut during boost gauge install....

[bigdo26]

Just as the title says - what is this wire? It was right behind the vacuum line I cut to install my boost gauge today, and it got cut as I cut through the vacuum line. Car starts up fine with cable disconnected, but I'm worried it goes to an important sensor of some sorts. Help is appreciated:

[nycion]

How the hell did you manage to cut that?

[The_Jerbel]

EGT sensor. You could try splicing it, but I'm not sure how well that will work. That was an expensive mistake if the splicing doesn't work.

[hercfe]

You're going to need high temp wire splices with very low impedance. You could use just any splice and it would work, but most k-type thermocouples read so accurately that any change in impedance can throw it off drastically.

[Mooseimage]

That wire connects to the following sensor, EGT as everyone stated above:

[bigdo26]

How the hell did you manage to cut that?

Cutting 'blind' - got the vacuum hose in the cutters and cranked down on them, realizing after that the EGT sensor wire was directly behind the vacuum wire. dumb mistake...

[bigdo26]

OK next question - this one goes to drivers side sensor? Or passenger side?

Lastly, with this cut, it should through a CEL, right? With the other EGT sensor working fine, will the car be drivable until I get a new EGT installed?

Thanks all - can't believe my horrible luck (it was my own fault of course...)

[Mooseimage]

The one you cut is the driver side.

Car will start, it's just a matter of how it will perform with a sensor that can't detect if the exhaust gas temp has been raised. I'm not sure about the CEL and performance of the car though with it cut.

[bigdo26]

Thanks - figures it's the drivers side, more difficult to get to.

Took the car out for a drive, and it acts pretty normally. It boosts to about 16psi in 6th gear on the highway (2500-3400 all I did), but when I let off the gas, it "clunks" real hard, which it's never done before.

I'll just get the new EGT sensor to install. PITA

[maniac33]

Yeah that's the driver's side as stated above, i just replaced mine took me a while to figure out how to get to it and be able to make enough room to get a wrench in there to break the sensor loose. If you need help PM me and i can help you out as much as i can. When i had cut mine it didn't throw a code, but my performance changed drastically after i put the new one on.

[DanS4]

its not hard to install. It should take more time to find the correct wrench. If i remember it was 17mm maybe 19mm. i tried 5 different wrenches and only one worked. i say i took me 15 min to install. 45 min to find the correct wrench.

[maniac33]

It was the opposite for me 45 minutes to do the swap 15 minutes to squeeze my big ass hands into the small ass spaces. And you are correct it is a 17mm wrench! For me i also had to move the heat shield that was covering the drivers side sensor and take out the secondary air pump and all that junk.

[bigdo26]

Yeah that's the driver's side as stated above, i just replaced mine took me a while to figure out how to get to it and be able to make enough room to get a wrench in there to break the sensor loose. If you need help PM me and i can help you out as much as i can. When i had cut mine it didn't throw a code, but my performance changed drastically after i put the new one on.

Appreciate the input. Hopefully I'll tackle this next weekend. If it's not too hard to break the sensor loose, I'll probably be OK. Kicking myself for snipping through the cable though, can't believe I did that!

[QWKDTSN]

That sucks! Anybody could have done the same thing. This is what happens when there's no room to work in an engine bay and you have to work by feel without being able to see what you're doing.

[gointoscott]

When my passenger side egt was failing the CEL light did not come on. But I did get a EGT code. I'm guessing you will now have EGT short to ground code. Lol. The drivers side is more difficult because of harder to get to. The passenger side is piece of cake. I am surprised it still boosts to 16psi. Usually your car will go to limp mode when a EGT fails. Which will make it dogish and only boost to 5psi. Unless the company who chipped your car had the EGTs coded out to not effect performance??? IDK. Just trying to think hoe it still boosts normal. Its good you are fixing right away. RunnIng with defective EGT will cause car to run rich. Can foul out 02's, plug cat. Of course only if run for long period of time.

I just saw a bank 1 egt code today. Argggggg. These things are expensive new. What's the cheapest place you guys have found them currently. I think vast sells them. Or www.genuineaudiparts.com has a competitive price on these. The last time I looked.

When my passenger egt went. I bought a used one from shokan. I think it was about 100 bucks. Maybe a little less.

[spyder101]

Damn man! Audi ONLY sells them by the pair's now. Can't buy them seperatly unless it's aftermarket or used and they run around 600.00$ for the pair.

[The_Jerbel]

I can still get single OEM sensors for a pretty reasonable price.

[bigdo26]

Found a used one for $75 that should arrive next week. Also pure motorsports PureEM sells them separately for ~$230, or $350 for a pair... best deal I found

I don't think the EGT sensor is tuned out, as I have a standard GIAC chip... I'm trying to stay out of boost though because is "clunks" real bad when I let off the gas after hitting 10+ psi, which I have to imagine is a bad thing!