My 2k has 48,000 miles on it and it ran regular gas for a long time and pinged a bit until i started to use premium a month or two ago...should i replace my spark plugs now and what brands have you found to be the best...custom maxima sells Denso Iridium Power Spark Plugs for $16 each...any good?

 

platinum is the way to go....
some people even use copper...but only use copper if you wanna change them frequently

 

oh btw NGK platinums is what the cars come with...and pretty much most people keep them.
I personally have Bosch Platinum +4 plugs.... but shortly after i changed em...like 3 weeks my ses light came on....not sure if its from the K&N filter i put on or the plugs? or neither....

 

i'd yank those bosch's and stick in good ol NGKs. but that's just my opinion...

 

NGK baby! I put in platinum ones around 51K on my 2K1.