55K mile spark plug change with picture!
 

Hi Guys,

This is my first post here, but I've been lurking for a while and trying to learn as much as I can. I purchased a 2005 RX-8 Shinka in November as a winter car (I drive a Supercharged C6 Corvette in the summer). Pretty happy with the car; I got a good deal on it, it handles great and has pretty adequate power for winter driving. Not as impressed with the fuel economy and oil consumption, but I know its been beat to death here.
Anyways, I noticed that the car has a dip in power around 7000RPM; I assume this is not normal? Not knowing if all the maintenance had been performed, I went ahead and did:
Oil Change, Air Filter Change, Cleaned MAF, Seafoam treatment, new coil packs, new ignition wires and new spark plugs.
The car ran fine before, and still runs well now. The hesitation is still there as is a check engine light for "Evaporative system leak" or similar that's been there since I bought it (I replaced the gas cap and it didn't go away).
Any other thoughts on what could be causing the dip in power @ 7krpm? It is slight; is that just normal with these engines?

Oh, here is the picture of what the spark plugs looked like at 55000Miles. I think they had never been changed (they did come right out though; none were even close to being seized on):

Attachment 248357

look at the dyno thread . It is normal to feel a slight dip - although to me it always felt more like a slight bump in power .

because APV opens at around 7200 rpm. so you "might" feel a very slight dip in power. but once the air starts flowing (less than 1 second) power goes up again (not torque tho, peaks at around 5.5 K)

those plugs are bad. at least you got it out. but I think your engine is all carbon up now, you might want to give your car a few minutes of HARD ASS run on highway (2nd gear all the way)

As for EVAP leak, it depends which one you got, most of the time its Gas cap, sometimes its the valve. so you have to know which code first.

mines got 66k miles on i think the stock plugs. we will see what mine look like today lol