Missfire after 4k miles?!
 

Just had the LS1 replaced with a crate LS6 4,500 miles ago. Obviously had the plug and wires replaced, among other things, with the MSD 8.5mm wires and NGK tr55 plugs. About a week ago, I'm noticing the car feels and sounds different. It's VERY sutble, but I know it's there. I can feel it in the idle and I can feel it on acceleration. I can also hear it at idle and I can hear the difference under acceleration. Now... the difficulty in being 100% sure about the car missing is that A) it's a manual (can't power brake) and B) it's got a healthy cam (236/242 114) plus headers and catback.

Now, is it possible that a plug is failing me after only 4k miles? Interestingly enough though... NO CODES. I will replace the plugs and wires if it's necessary but I'm trying to avoid it if at all possible due to how painful that task is. I know the coils rarely go bad, but it is a possibility(?) that I can't rule out just yet. I did have the car tuned and injectors upgraded to 42# injectors if that makes a difference. Other mods are in the sig. It's just super strange to me to have a plug go so early.

If I think of any other info. that might be useful to figuring this one out, I will post.

Take it back to your tuner?

What would the tune have to do with anything after 4,500 miles?

I didn't even realize you had no codes. Its not misfiring if there are no codes.

There is a definite loss of low end power... plus, I can hear/feel it in the lower RPMS.

I guess I can just bite the bullet and change the plugs and wires and see what I've got...