Hey, I just bought a 1998 A4 and am wondering if you guys could help me out with some things. The CEL is on so i used a VW/AUDI Memoscan that the previous owner left in the glovebox and got two error codes: (16806) and (16517). The oil temp gauge as well as the engine temp gauge don't work. This may be me being paranoid but the engine seems to be running hot and when i shut it down it gives off an odd smell, but since the temp gauges dont work im not sure if its normal or not. Two other unimportant things are the airbag light is on, and the little square digital monitor on the dash that tells you the outside temperature and your mileage flashes on and off randomly. Any ideas/answers for any of these problems would be greatly appreciated, Thanks

 

16806, probably burned out catalytic converter.
16517 bad front oxygen sensor;

Check to see if they are present of if the previous owner just cut them out and put in a pipe.

 

16517 - Oxygen (Lambda) Sensor B1 S1: Response too Slow

16806 - Main Catalyst; Bank 1: Efficiency Below Threshold

Sounds like an O2 sensor going. The rest of the problems, no clue other than you prolly need to look around for wiring problems. Whats the miles?

 

its 105, 000 miles. How important is it to fix the cat/ O2 sensor?

 

It depends, if your state requires inspection your car won't pass. Also, you are going to suffer on your gas mileage. My advise if you don't want to spend a lot of money, find someone who will sell you a used oem cat and buy the sensors new, they don't cost much.

 

thanks a lot for all the help