P0300 ( I have searched)

[Jaunt]

I rarely post on forums because I can usually find the answers through searching. My car (01 S4) threw the P0300 code. After researching I decided to just install the ECS ICM delete with TFSI 2.0 coils and the Bosch Sidefire plugs. After the install the code went away and had no more misfires under boost for about 3 months. My idle is still a little rough but I think that may be the Siemens 630cc deka injectors. My battery died after letting the car sit for 3 weeks. I replaced the battery and drove the car. After about 50 miles of driving, my CEL came back on (while driving normally, no boost at about 45 mph). Checked the code and it was P0300 again. After researching last night I took a look at the ICM/coil harnesses. No issues with the wiring or the plugs. I am trying to find someone with VAGCOM in central MA becasue that may shed more light, but in the mean time I am looking for some direction from you guys. Thanks in advance.

[bajanavant]

Check the wires inside your engine harness

[Jaunt]

Will do, I should also add that the car has no issues boosting.

[christianb5s4]

Did you check the spark plugs to see if they are gapped correctly?

[Jaunt]

Did you check the spark plugs to see if they are gapped correctly?

They are the sidefires so no gapping needed.

[christianb5s4]

I have seen other threads where people had this issue with sidefires, if I dig em up I'll post the links. I looked into it before I found out my misfires were due to crappy no brand coilpacks as I also have sidefires.

[zillarob]

I think somebody had a prob just a few weeks ago with the f5dpor.
One was closed (prob from dropping it in the plug well), jhm gapped them and seemed to help.

Being that you had misfires before, may be something other than the plugs. They are easy enough to check so def do that first. You have the correct heat range?
Log misfires with vcds to figure out what cyl(s) and go from there.

[Jaunt]

I have seen other threads where people had this issue with sidefires, if I dig em up I'll post the links. I looked into it before I found out my misfires were due to crappy no brand coilpacks as I also have sidefires.

Ahh ok, appreciate it.

I think somebody had a prob just a few weeks ago with the f5dpor.
One was closed (prob from dropping it in the plug well), jhm gapped them and seemed to help.

Being that you had misfires before, may be something other than the plugs. They are easy enough to check so def do that first. You have the correct heat range?
Log misfires with vcds to figure out what cyl(s) and go from there.

I will check them tomorrow, dont know why I havent yet, figured they would still be ok seeing they only have 100 miles on them but no big deal to check them. The misfires I had before went away for about 4 months after I deleted the ICM's and installed the 2.0 coils. The misfire code came back after changing out my battery. The car doesnt feel like its misfiring at all, maybe slightly at idle.