Or inspect the plugs as someone already mentioned. Also, you might be able to borrow a knock sensor from your local tuner.

 

I was wondering if its ok to use the lfr6aix-11 ngk iridium IX spark plug heat range on an N/A coupe? Will it cause any damage or engine codes? I got a really good deal on these they were less then the stock heat range. I wanna go ahead and find out before I install them cause I really hate to have to do things twice lol...

 

i dont think so, if those are a colder range they may have a tendency to foul more than the normal plugs

 

Any updates from people who have tried the colder plugs on an NA motor? When it's hot outside, I occasionally get some knock at low to mid rpms when I first get on the gas pretty hard. The knock may still be there at higher rpms, but I wonder if I just can't hear it over the intake and Borla catback (my only engine mods).

I also occasionally get a weird change in exhaust tone when engaging the next gear from 1 to 2 or 2 to 3 at WOT. The only way to describe it is the normally amazing growl of the Borla system seems to go "off-key"...like hitting a wrong note on a piano. It only does it for a couple seconds and goes away, or it will go away immediately if I lift and then go WOT again.

I wonder if these two things are related and if the cooler plugs might help.

 

^+1 I am currently experiencing the same issue when I get on the gas at highway speed (65mph) in 4/5th gear. In for a educated response.