nauset

1995 A6Q 5speed. Starts and runs fine, no warning lights. Milage suddenly dropped by 2-3 mpg. No gas leak or gas odor in garage. No "tune-up" for years, car has 58K miles. If need tune up should start or run rough? If a sensor should trigger fault light, no?

SilverS13

It might be time for a tune up, but first thing check your tires and the pressure to make sure they are correct. Try putting some of the seafoam cleaner in your gas tank when you fill next time too. That should work.

Ben2

Does your check engine light work when you first turn the key? I've had cars where it burnt out and I never noticed.

nauset

Thanks for help. Light does not seem to work-good call. I'll investigate and let you know.

nauset

Interesting that light not working. I replaced and now works but did not signal a fault. Tires=OK. I plan tune-up and Seafoam as suggested.
Thanks very much.

Ben2

Try blinking-out any stored DTCs. Not all trouble codes will trigger the check engine light, but they might give you an idea of what's happening. Instructions are in the FAQ.

http://forums.quattroworld.com/a6100/msgs/3.phtml

If you haven't done so, too, carefully check all the vacuum lines, esp. the ones on the driver's side of the engine that run along the top of the cylinder head back to the brake booster. These tend to go bad and leak causing all sorts of strange problems.

nauset

Thanks very much for your help. Vacuum lines appear intact and in decent shape. I could not find dtc code instructions in AudiWorld (there is no adapter strap in the relay box) but I'm new to site and will keep looking.

tela

You have a 5-speed and it only has 58k miles?

I think you should probably sell it to me.

nauset

Still having trouble finding the instructions (FAQ) for blinking out codes. There is no adapter strap in the relay box. Any hints?

Ben2

Here's the post:

http://forums.quattroworld.com/a6100/msgs/6211.phtml

The strap is just a regular wire with a connector on each end to fit. You could use a wire with an alligator clip on each end or just a regular stripped wire in a punch just as well.