Roughly how much should it cost to repair an o2 sensor on a 2004 Audi A6? My mom's shop charged her $405 for the part and $500 for labor. Is that in any way reasonable? Seems high to me.

 

To change all four sensors...maybe, though if it takes a mechanic five hours to change all four sensors you need to find a new mechanic. Definitely not even close for just one. But if you are going to do one, you may as well do all four.

 

Thanks. That is about what I figured. I thought the part should be more like $150-200 and the labor should be around the same.

 

If $ 405 is the quote for all four sensors, then it is ok. They'll make their money via labor charges ($ 250-300 probably) - unless they use "universal type" O2 sensors that are cheaper.... so it takes a while to wire all 4 connectors and install them.
I would say buy your own, good sensors, replace them and forget about that issue. You car will die before those NTKs will.

 

Sadly, the $405 was just for one sensor. And the $500 labor charge was only to replace that one sensor.

 

Start becoming the "wrench man" for your mom: oil change, air filter change, spark plugs, etc - maintenance, easy stuff like that. Unfortunately the "recession" seems to be hitting only the customer's pockets, not the businesses'...

 

Was it the front or the rear sensor? Anyways, sorry to say, but she got hosed.