autoGTa6

I was about to say this sounds like misfires... When overloading with fuel and meth at the track, I would see my check engine light flash and I would bog out of the hole. First gear would be fine and when second grabbed it would bog/flash the check engine light. This problem sounds like it might be related to the ECU overloading fuel or something is wrong with your fueling system. IMO of course.

donromani

Hmm...it's strange for both the egt's to go at the same time, but the EGT 2 is kaput according to the VAG. Your O2s are just old, you can replace them if you want to, but you don't have to. I dont know what the 18010 - Power Supply error might mean, but maybe there is an electrical issue that was caused by, or is causing the EGT failures.

autoGTa6

When are your fuel filter changed? Check the date on the filter and get back to us. I think this might be the first thing you check.

complacentsee

The power supply one usually means you disconnected the battery.

complacentsee

17866 - Exhaust Gas Temp Sensor 2 (G236): Short to Ground
P1458 - 35-00 - -
17861 - Exhaust Gas Temp Sensor 1 (G235): Open or Short to Plus
P1453 - 35-00 - -
17539 - Oxygen (Lambda) Sensor; B2 S1: Internal Resistance too High
P1131 - 35-10 - - - Intermittent
17869 - Exhaust Gas Temp Regulation for Bank 1: Implausible Signal
P1461 - 35-10 - - - Intermittent

Sounds like classic EGT symptoms. I would wait do deal with the O2 sensor as it is ittermitent. You could always go ahead and do it as well. But usually something like that I clear codes and wait for it to come back/go away.

donromani

Comp, do you know what the diff. is between open short to ground and open short to plus? Open to ground I read as: the internal components of the sensor are broken, but what does open to plus mean? I assume current is being routed back to the positive battery terminal? What could cause that?

Turbowins

I have a replacement on the way from vast, and I figured atleast one of my EGT's is bad by now but I had another question about this particular code:

17539 - Oxygen (Lambda) Sensor; B2 S1: Internal Resistance too High
P1131 - 35-10 - - - Intermittent

I was inspecting the engine and drivetrain parts the other day and just so happened to notice that my second 02 sensors have already been relocated to the rear of the main cats with the front bungs blocked off, so Im guessing I already have piggie downpipes? However, if so, could this code be telling me that one of my main cats is starting to clog?

complacentsee

This purely means electrical resistance. O2 sensors are one of those really hard to understand sensors. There is a huge array of things that can go wrong. Some of these being:

Internal shorts to B+/Ground
No Activity
Heater failure
Electrical Malfunction (I think that is a code on ours)
Internal Resistance too high

Unfortunatly here it gets more confusing. The S4 has 4 oxygen sensors and 2 Exhaust Gas Temperature sensors. The ECU needs to know the exhaust gas temperature at all times. So you would obviously think that the EGT would be giving the ECU this data direct. However, this is not the case. The EGTs are actually only used as a "fail safe" and can only read temperatures in the 950-1050 degrees celcius range. Throughout the rest of the range of temperatures, the Oxygen sensors' internal resistance is used to calculate the exhaust gas temperature. In an oxygen sensor, the internal resistance decreases with the the temperature. Therefore, if the oxygens internal resistance is too high it must be cheaking against another known value.

I don't know however if it is checking the temperature against the other bank's oxygen sensor of the EGT sensors. If it is the EGT sensors, than you might have nothing wrong with your oxygen sensor. I would say you probably will have to replace it anyway, but I can't be certain.

complacentsee

Well, as you remember. I tried to prove this theory of mine by soldering in a new EGT electronics board into my failed sensor. I still don't know if it was the weak leg solder joint or if there were more issues that caused me "repaired" one to fail. lol Maybe internal to the EGT probe, the 2 dissimilar metal leads can short to the case after time. This would result in a short to ground.

Turbowins

Can someone tell me what hose/fitting this is? And I took off my lower turbo to intercooler hoses and found a little oil in the drivers side pipe. Didnt come spilling out when i took it off but can someone tell me if this is a significant/concerning amount? about the same inside the ds intercooler