Intermittent engine power loss
 

I have a 04 GT with about 49k. For the past 4 weeks or so I have been experiencing a weird intermittent loss in engine power. It feels like the breaks are being applied when I'm accelerating. It's usually below 4k RPM and really bad below 1500 when I'm just getting moving. It is worst when the AC is running but still noticeable if I turn it off. It has been very hot and humid lately but that has not affected the RX-8 like this before. However, today it's been significantly cooler outside and it's running just fine :dunno:. Any thoughts?

It might be the cat, I'm having the same problems!

Really!? Is it possible to determine that is the case without going to the dealer? Is that covered under an extended warrenty?

Typical checklist for power loss:
1) Ignition- This can be coils, wires, or spark plugs.
2) Cat- Beginning to clog... though typically should be more noticeable at higher RPMs and then at lower RPMs as it gets worse.
3) Vacuum leak- Somewhere in the intake setup.
4) Low Compression- You'll need a compression tester to verify this.
5) Seized brake calipers- Often overlooked, but affects lower RPMs since the pads are riding the rotor. Easy to check this... jack up the car and spin the tire, if its difficult to spin, its seized.

With 49k miles if the coils and plugs have never been changed then I would start there.

How hard is a plug and coil change? I did a quick search for a DIY and couldn't find it.

Maybe instead of a "quick" search you should take a little more time since there are a couple threads in the DIY section for this:

coils
https://www.rx8club.com/showthread.p...ht=spark+plugs
plugs
https://www.rx8club.com/showthread.p...ht=spark+plugs

Are stock coils and plugs the way to go or are there good vendor kits to get instead?

OEM plugs are the best you can get for this car. OEM coils and plug wires are pretty good but there are some better options outthere if you can afford the price. If you want to upgrate your ignition system you should look at the BHR kit. Look here:
http://blackhaloracing.com/products-...tion-system19/
The vast majority of the forum members acknowledge that this kit is the best way to go if you are looking to upgrade your ignition system.

Update everyone

I changed the plugs and have noticed no difference. Any good test for the coils? The maintenance schedule didn't' say anything about changing the coils at 30k. Also any test for the cat to see if that's it?

plugs - coils - wires all at once, not just plugs... read the threads above harder...

Clean MAF?

it is an 04 so he should really be looking at putting in an oil catch can if im not mistaken... but cleaning the mass air flow sensor and doing an ssv check an dclean wont hurt.

Picked up coils and plugs today, I'll update after the install tonight.

Just finished the install and she is all back to normal! Thanks for the help everyone, much appreciated.

For future searchers with the same issues replace the coils, wires and plugs. See above links for DIY.