Which one is Cylinder #8?
 

Straight to the Point: I have 2004 S4 with a check engine light that says "misfire on cylinder #8" but I don't know which cylinder that is? I've already changed all the spark plugs but still has the same problem so I bought an Ignition Coil, if there are any other thoughts let me know please.

The Whole Story: The good news. So I just bought my first Audi, it was a "Christmas Present" from my wife. A Silver 2004 S4 MT, can I say WOW!!! What a car, so far it's everything I ever wanted in a car, 4 Dr's, V8, 6spd, and RWD ok so the AWD is a bonus.

It has 86,000 miles on it with Black Leather and Wood Grain Trim, I prefer the Silver Trim so if there's anyone out there who wants to trade or something let me know. This was the only one I could find even close to my price range, was a toss up between the Silver and the Nogaro but the Nogaro is hard to find.

Now the bad news. After 100 miles my check engine light came on, car still ran fine, so no big deal I'll check when I get home. Read the codes and it says that "P0175 System too Rich (bank 2)", according to Auto Zone it's prob an O2 sensor, there are 4? That's no help, dealer says that if it was O2 it would say so, they'll run diagnostics for $105 and tell me exactly what it is.

I drove it one more day and on the way home it started missing, read the codes again and it said "misfire on cylinder #8", I don't even know which cylinder is number 8, it didn't come with an owner's manual and I haven't had the chance to get one yet, let alone the service manual.

Figured I'd start with the spark plugs, change oil, and air filter while I was at it, was planning on doing so after the new year anyways.

Put it back together and still the same thing. After reading about it on the forum I figured it might be an Ignition Coil which is only $35 so I ordered one, no one local has anything for this car, had to order the Air Filter too. Now I just need to know where cylinder #8 is? Any help would be greatly appreciated.

I guess a good deal isn't always a good deal, I'm hoping I can bring this thing back to life and start enjoying it for the wonderful car it is.

PS. Dealer talked me into a "bumper-to-bumper" warranty with $100 deductable but I haven't even been registered yet with the warranty company, it can take a couple of weeks, and besides if it's not that expensive to repair I'd rather do it myself. I bought it as a piece of mind in case something really serious goes wrong with it $500/yr for 3 yrs unlimited miles. Sounded good anyways.