Intermittant misfire code

[racingfast]

I have been getting a misfire code when hitting the rev limiter. Needless to say I have hit this "numerous times" without it happening. The only changes I have made that coincide with this is TPIS long tubes. Any words of wisdom?

[NETfiend]

Are you sure your only getting the misfire when you hit the rev limiter? A couple things you might want to check.. First of all, make sure that your sparkplugs are torqued down properly. Improperly torqued spark plugs will sometimes leak electricity in odd ways randomly (this is especially important on aluminum block engines). Second, make sure that you don't have any cracked or burned plug wires. Longtube headers tend to melt or cause cracking to plug wires on occasion. Also, coating the inside of the sparkplug boot with some kind of dielectric grease might help prevent voltage from leaking off of the plugs. And don't forget to look over your sparkplugs thoroughly and make sure that the ceramic on the top of the plug isn't chipped or cracked as a result of being bumped while installing the headers or being overtorqued when they were installed.

Good luck

[racingfast]

Will go over all you said... I dont even FEEL the misfire, the scan tool said it happened at 6500 rpms at 99.9% wide open throttle... so I presumed it was the limiter. The plugs and wires are both new and we took the plugs out when installing the headers. The coil packs were flipped up over the intake. I know this will be hard to find, but it will be a long winter..
What is odd is that it started AFTER the header install.