I just installed NGK BPR7EIX 4055 on my 04 8 RS and after I started the car and it had a really rough idle. I turned the car off and checked to make sure everything was connected properly, it was. I turn the car back on and I got a cel, but my cool friend hooked up the scanner and deleted the code before we found out what it was. I drove home about 32 miles and the cel did not return but the idle is still rough. What happened?

Take them back out and check the gaps.

Any reason why you are not running the NGK BPR7ES (coppers)? Mods?

.026 all 4

Actually it was in stock and the car is stock.

Isn't .026 a bit too much on the stock coils? I thought you are suppose to be at .022.

+1

what were they gapped to before? try .024 and if not .022.

I run the same gap on my BPR7ES with no issues whatsoever.

This was after the rough running??
I would double check the plugs again, signs of cracking.

Good Luck

Stock specs
2003-04 .028-031

2005-06 .020-024

Most run .026 but max spec for 05-06's is .6 mm. .026" is .66 mm. Stick to specs unless you get to 26 psi of boost. Then tune your plugs with the rest

for 2005 MY, specs are .024-.026". I dont know for sure if that also applies to 2003-04 though.
If your stock you shouldnt be having to gap smaller than .024". Even running them at .025" you should be fine. Something else is wrong, are you sure the coils and wires are in the correct cylinders?

You can't really mess the the firing order up since the coils bolt down and the wires run right to the other two plugs and the coils are the same.

Pull the in injector harnesses, one by one, until you find the cylinder that is misfiring. Unless your friends code reader can disable injectors.

+1 bet you got a cracked plug or something along those lines! also maybe when you pulled the wires out they got messed up check inside the wires and make sure its all good!

I just put in BPR7ES gapped to .030, no more problems.

Thanks for all the help!





the code returned before I put in the the new plugs P0300.