Im going to end up doing that. Mmats, what ended up being your problem? I really hope its just a simple problem like putting the stock intake back on and checking all wires / plugs. It almost felt like a slight rumble, Im really not sure what else it could be. No power at all either.

 

Have you eliminated the plugs as a potential cause?

 

Same thing happened to me a few months ago & it was plugs/coils

 

If it stumbles as you increase RPMs and seems to be "choppy" through the rev-range, definitely go over your intake tubing with a fine tooth comb. Check all the hose clamps and all the piping - my car was stumbling all over the place a few months back, it turned out a small part of the intake tubing had popped itself off and the car was a total mess because of it.

Failing that, I'd say it's likely plugs/coils like a few posters have already pointed out.

 

a vacuum line? loose spark plug wires? Loose intake? A mazdaspeed intake that was designed for the RX8 will NOT void ANY warranty. But it would be a wise idea to just change everything back.

 

Yah, going to into the dealership reading them the Magnuson Act might as well be the Riot Act. It's not going to be well received.

 

Im not too car savvy. I usually have my friends help me out with anything, but im sure it cant be too hard to check the plugs out etc. The plugs could definately cause a flashing CEL though right?