mayhem100

2002 A4 3.0Q tiptronic.

Got P0300, 0301, 0303 and 0304 on the car for a second time. 300 indicated multiple misfires, 302, 303 and 304 indicate misfires in cylinders 1,3 and 4.

Bad coil packs? If so should I replace just the three or all 6? If not, what else is a likely cause?

Thanks in advance.

kr964

It is unlikely that all 3 coil pack got suddenly shot.
Very often misfire on just on cylinder disrupts ignition on others throwing the codes.
Try clearing the codes, start it up and watch which code shows up first, it'll indicate the cylinder #. It also may be bad spark plugs (replace all of them of they have more than 50K miles).

mayhem100

I got the same codes about a week ago. They displayed on the code reader in the order 300, 301, 304, 303. I did notice a stumble at idle at that time.

Cleared the codes and a few days alter the CEL came back on, codes were the same and in the same order.

This is using an ODBII code reader, I do not have a VAG-COM available to me.

Car has 70k on it, we've owned it since 40k and I have not changed the plugs, not have I inspected them for condition. I do not have prior maintenance records so I don't know if the plugs were ever replaced or not, probably safe to assume not though and easy enough to do. Any specific plug recommendations? Car is modless, so I assume OEM or OEM direct replacemetn is the best choice...NGK or Bosch or whatever is used commonly. Must be something like $10-12 a plug I presume?

I'll hold off on the coil packs for now...or should I grab one and do the #1 cylinder since thats the first misfire?

Thanks for the help.

kr964

Usually you do not have to wait for the CEL to get a misfire code.
Right after you clear the codes, drive the car slowly for a few minutes in a high gear (lugging the engine a bit to induce misfire). If there is even minor misfire, the ECU should register it as pending (no CEL yet), then you can read the code on your OBD2 scanner (no need for VAG-COM to do that).

But it sounds like the spark plugs were not replaced since new so I would do this first.
(you may also want the change the air filter while at it).
I do not think there is anything better then regular OEM plugs (they are NGK Iridium I think).

It is possible that one th

mayhem100

I'll just opt to swap the plugs out. I tried to take a look this morning to see if the #1 was fouled and I'm embarrassed to say I have no clue how to get the darn cover off the top of the plug. How do I go about changing the plugs on this thing?

I'll grab a new air filter while I'm at it and then clear the codes and retest it.

Thanks.

kr964

The top of the plug is the actual ignition coil (red L shaped tube with flat head that it pushed onto the plug).
You need to push and pry off the wire connector with a flat screwdriver and slide it down.
But before you do this you'll need to undo two small torx screws that hold the wire to the valve cover.
The wire's plastic cover is pretty stiff so you may need to disconnect all 3 coil connectors to be able to move it down. You may want to search the tech forums for more detailed step by step instructions and pictures.