I was getting backfire after header install. I did a number of things to try and correct it. Change o2 sensors, got a basic tune and still ended up getting popping sounds. So I thought I would check my plugs. I ended up changing the plugs on the passenger side because I really dont know what a bad plug looks like. A friend of mine took a look at #1 and #3 and said they were good. So if I'm getting popping sounds from the exhaust then I'll need to check #5 and #7, I didn't get a chance to check those. But below are pictures of the plugs I removed from the passenger side. The pictures might not help but let me know what you think anyways.

 

whats kind of plugs? and what did you gap them to?

 

i had the same thing happen to me and I just swapped my plugs and it went away...

 

They're the tr55's and they were gapped at .50 like what everyone else is running.

 

I hope it goes away then

 

Although the pictures aren't the best, the plugs appear to be in good shape without any buildups on them. Have you also checked your plug wires and are you sure you don't have any exhaust leaks?

 

I might have an exhaust leak but I didn't know it would cause backfire?

 

yep

 

Well I forgot to mention that when I took off a couple of my wires, they looked a little burned. Do you think that may be the case?

 

If they are burned through enough where they are grounding out to metal, then this could cause your problems as well.