A6 automatic seems to be not downshifting correctly

[quinnrj]

I have a 1996 Audi A6 (2.8 liter, 30 valve, automatic) estate that's been displaying a strange problem:

At first, it would begin missing (losing power) when going uphill or accelerating. It almost seemed like it should be downshifting, but wasn't. Later, it would start missing more often, and the gas mileage would drop.

Then, I changed the ignition coil & fuel filter. It was driving perfectly for 3 weeks, then the same problem appeared. It started missing when it should have been downshifting. Then, it got worse & started missing more often & the mileage would drop.

Then, I changed the HT leads. It was perfect for about 3 weeks, then the same problem appeared - missing when it should have been downshifting. Now, it's starting to miss more often.

I am ready to change the plugs (though I changed them in November when the problem began), but am perplexed as to what could be going on. Any ideas?

FYI: I'm going to be getting rid of it in two months (selling it if it passes MOT or junking it if it'll cost too much). Any ideas how much it could sell for?

Thanks.

-Bob

[Crasher]

Why instead of wasting all that money on parts didn’t you have a simple £30 fault code read carried out on the engine and box ECU’s? It may just be a simple sensor problem.

[quinnrj]

Why instead of wasting all that money on parts didn’t you have a simple £30 fault code read carried out on the engine and box ECU’s? It may just be a simple sensor problem.

The first thing I would normally do would be to check the computer readout, but Halfords & GSF (the two places I went to) don't read computers. The worker at GSF said it would be useless to read the computer if the check engine light was on. Was he wrong?

Where can one go for a 30 pound fault code read? I moved to England from the USA last summer.

I think all of the parts were warranted, because, despite my current problem, the mileage is still better than it was last summer.

Thanks.

-Bob

[Crasher]

Any decent well equipped modern garage can do a fault code read for you. It may show no faults on the engine or box but that is not a bad thing as it eliminates a huge list of potential problems but the person who told you that a fault code read with the MIL not on (presumably what you mean as you infer it is on) was useless is himself useless and completely wrong as your car does not even have an MIL, only cars built for the US market have that but it does have quite reasonable on board diagnostics, 75 possible engine codes and 47 on the gearbox. Which engine code is your car, ACK?

One other question, having been to the USA a few times, what on God’s earth possessed you to move here? I would love to get out of this dump!