Heres the deal. I just got done doing an ls6 swap with Fm14 cam/springs etc. Did the 90/90 combo and the car is throwing up misfires like crazy. Throwing PO300 code and ALL 8 cylinders are misfiring. It throws the SES light sometimes and sometimes it doesn't. Using HP tuners. Would setting the misfire tables to 32000 or 32767 fix this?? Let me know ASAP!

 

Big cam will elevate misfire levels. I'd go a little less
extreme in bumping up the thresholds, like if there is
a random misfire "noise floor" of (say) 100-300 counts
then set the misfire threshold to 1000 or something
sort-of-sane, just so you're told if it heads south.

It's kind of like a compression test, the absolute misfire
count is not so much the indicator, as the match
between the cylinders. If they're all about the same,
just more "jiggy", set the bar just a stretch above
"normal max".

 

Take a look at your main harness conector for your coils, it might be fliped around on one or both sides.

 

well that cam will lope a lot and when it lopes its kinda like a misfire because your intake and exhaust valve are open at the same time and computer thinks its missing.