[cstraface]

Only get the misfire code with a tune installed - first it was the original JB (about 3 months ago before I pulled it b/c of the misfires) and as of yesterday, JB4. No CEL stock, although I have noticed the famed "hiccup/groan/cut-out" at WOT around 3,500-4,000 RPM.

I know, I know - most likely coil, plug or injector. I think I'm going to pull the JB4 and just take it in. Still have 10k left on original warranty.

But here are my 2 questions: why does the tune exacerbate the problem? One would think a bad coil or a bad plug is just that...bad and not working properly. A stock engine still needs to fire that #1 cylinder...right? I can possibly see an injector...do the tunes increase flow or pressure or something? Am I eligible for the injector recall? 4/07 manufacture date.

Question 2, would you guys leave the misfire code, pull the JB4 and head to the dealer? I'm worried if I clear the code, pull the JB and take it in I will get the old, "Technician could not replicate" bull.

[wren57]

1) Because it increases the demands on the engine: ignition, fueling, etc

2) Remove JB4, clear codes, drive around until you get the CEL again.

[cstraface]

That's the problem...I don't get the CEL driving around stock. Well...at least I haven't prior to...