Hello all, I am new here and looking for some help, please!!! I have a 2003 A4 Quatro that started random Misfires codes P0301/2/3/4, I clear the codes and they come back sometimes just P0301 and 4 or some other variation. I replaced all 4 coil packs, spark plugs, and MAF sensor. Still I get the random misfires, anyone have any ideas on what this could be, I am stuck at this point.

Thanks for any help.

RB

 

i would guess gaps are off. If stock, they should be .032 and if you are chipped, they should be gapped down to .028.

 

Go to the dealer and see if you ECM has been re-flashed to an updated version, there was a TSB for random miss-fire faults on the 1.8T engine that didn't really exist.

 

Thanks for the updates, I will double check the Gap on the new plugs. I will find out about the ECM version. I should have mentioned that it runs extremely rough and the check engine light starts flashing when at idle. When the engine is over about 1200RPM it runs good, it just starts running rough and shaking when at idle.

Thanks again,
RB

 

Well if its that bad, then it probably has nothing to do with the version software, check the plug gas like cincy said, and pull the fuel injectors, they may be clogged for some reason.

 

Thanks, I pulled the plugs and they are gapped at .032, tested and it still runs really bad. I will have to plan pulling the injectors off and having them tested. Any other suggestions on what could cause this.

Thanks again,
RB

 

You may want to try and gap the plugs down to .030 and give that a try. I have seen other cars run poorly until the gaps of the plugs were gapped further down than normal. ALso, what plugs are you running?

ANother thing you should do is inspect the coilpack harness. It is know to crack sometimes and cause misfires over all 4cyl awell

 

Thanks for the help, I am about to pull my hair out!! I am using the NGK plugs from the dealer PFR6Q I re-gapped to .030, cleared the codes and let it run, as soon as the idle came down it started shaking and CEL came on. Checked the codes P03400/1234 were there.

Thanks again for your help,
RB

 

try taking them down to .028 and if that doesnt clear it, time to start looking elsewhere. If you have a tq wrench, make sure its at 22ft-lb. Also make sure the end of the packs are clean. Also when your out there, check all the wireing and then maybe the injectors like mentioned above.

 

I checked the wiring with the multimeter and got one real variance from the other wires. Not sure if this is something so please let me know if I am going in the right direction. Tested all coil pack wires to each pack, the variance was on Cylinder 3 pin 3 it showed around 56-58 when the other cylinders 1,2,4 on pin 3 showed 50. Is this normal or is this pointing to a bad coil wire?
If I have not included enough info please let me know!
Thanks for any help,

RB