I'm sticking by my "catalytic converter theory", especially now after finding out about numerous flooding events. Pure fuel gets sent through the exhaust, car heats up, burns fuel in cat...melts cat. Ask me how I know.

If you are within warranty, have the stealership check it out.

 

I'm having similar problems also except for startup. It takes 2-3 seconds more than usual to crank it and it's the same whether the engine is cold or warm. I thought I was imagining things if not for the fact that I now have a hard time going up the ramp to get out of the garage every morning. It has no problems getting to red line but it's just sluggish below 4k rpms. Car is at 45k miles now. I just changed the air filter and plugs at maybe 2k mile before that. This is my third set of plugs. I'm still at the original coils and wires. I've tried the simple stuff like dry gas and cleaning the MAF sensor. I also have a slightly rough idle. It will stay at ~850 most of the time and I'll feel the vibration on the steering wheel. Occasionally, it dips down to 750 and then bounces back up. Cleaning the MAF improved it a little but not fully.

I'm gonna change the coils and wires this week and see what happens. I've taken it to the dealership and the only relevant code they pulled out is misfiring in rotor #2. The tech also eliminated a bad MAF by testing a brand new one. I'm hoping that the coils and wires are the culprit. If they don't do anything, I'm wondering what the next steps are.

Edit:
For further disclosure, my car is 2004. Never flooded. Here are the pics of my old spark plugs. If I'm not mistaken, both the trailing ones are kind of fouled. These are my 2nd set of plugs replaced at 21k miles along with new battery and starter for some TSB.

Update:
It appears that the sluggish response and hard starts are caused by at least one bad ignition coil: https://www.rx8club.com/showpost.php...0&postcount=29

 

Between the 45k miles you have on them and the misfire code, I can say its your coils. Coils typically get replaced at 30k or less. I would do the wires too just to get a fresh pair on. Let us know how it goes. Should only take you 20 minutes or so.

 

It was the ignition coils after all. After swapping the coils and wires, the power loss and hard start problems have disappeared. Here's a pic of them:



The worst one was connected to trailing plug in rotor #2 that reported misfirings. The mechanic said that that plug was fouled black. We're both aware of Mazda's statement about white spots not an indication of a bad ignition coil, but I guess this is an exception? Anyway, the throttle response feels good now. The rough idle is not totally cured though, and I wonder if it's the engine mounts now...

 

You may want to replace your spark plugs too. Should yield slightly better mpg/throttle response. I do it yearly.

 

quick question. Anyone know where the ECU on the RX8 is located?

 

Front passenger corner..under the plastic lid

 

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