So the other day my check engine light came on (yellow, not blinking) I decided to take it to a mechanic, and when he hooked it up the computer it came out with these fault codes. I need you guys to tell me if any of them are SERIOUS and have to be replaced ASAP, also if they are going to do any long term damage if i do not get them replaced soon.


17977; Cruise Control Switch Fault
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Im not overly concerned with this one because i do not use cruise control.




17683; EGR Temperature Fault
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I honestly do not know what this is, what it does or anything else other than the EGR valve controls emission performance




17544; Fuel Trim Bank 1 Lean
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It seems this is the most serious from the reading i have done on the forums/google. Seems like it can be a valve problem. But i need to know what the danger in this fault is and how much is it to fix, etc etc.



Thank you all for your help in advance.

 

so......do you have like a ford or something? no but really, year/model

edit: from previous posts - 04 Audi A6 2.7T

 

Can anyone help me with this?

 

Well it's been a month, do you still have a problem?

 

yes i do

 

The EGR Temp Sensor is somewhat difficult to replace, but doable.
As far as the Fuel Trim code: have you checked all of the vacuum hoses? Start with those, replace any brittle and aged ones (even if they still look "still good"), and go from there. Even if the car is chipped and something is out of whack, you should still start with the vacuum hoses inspection.

 

The EGR adds a small amount of exhaust gas back into the intake to help with certain emissions. The temp sensor monitors how hot the circuit is getting and closes the valve if it gets too hot. I would get it fixed. It could either be a damaged harness or a bad sensor.
The lean condition could be a lot of things, as was said, check the vacuum hoses to be sure they are all connected and not leaking, check the intake between the MAF and the throttle body for leaks, Since it's apparently just one bank running lean, its probably something particluar to that bank, so that leads me to think you have a dirty, dribbling fuel injector on that bank. This is just a start, but I would get it looked at soon, an off mixture is always bad for the engine. My suggestion is to get the engine scanned in real time to monitor all the sensors, you could also have a lazy O2 sensor on that lean bank, the scan will find it.

 

nm320 was not kidding when he asked about the year /model.
Many answers are dependant upon the year, motor, 2 or 4 wheel drive, etc.
You'll get significantly better responses when you include the basic info.
Not all Audis are created equal...

Clear the codes and see what comes back.