List your steps for restoring lost HP!
 

I know things like changing the fuel filter, plugs, wires, flushing the fuel system, checking the O2 sensor, etc... what else can you think of would restore lost HP? Any steps of maintainance or a list certain components to replace would be very helpful. What's worked for you??? And more specifically, what would you do for an N/A?

All the things you listed are good steps. One that I am going to have done once my exhaust gets hear, is to have my injectors cleaned and blueprinted to restore them back to their original status. If your car has over 100K, it doesn't matter how much STP injector cleaner you run through it, you will NEVER get them as clean as they could be. Its only $25 each too. You can regain up to 5 to 10 HP supposedly(depending on how dirty your injectors are). Always doing compression checks after about 20K miles wouldn't hurt either if your that anal about your car...Not HP related, but having your brake lines checked or changed over to braided SS would help a lot to...as well as your clutch line. Checking all your vaccum hoses(or converting to silicone) is a good step to assure safe HP and a healthy motor too...thats all I can come up w/ right now.

And of course a rebuild should regain all lost HP in the motor :):)

I know you listed "testing the O2 sensor," but mine passed the shop manual test even at 100K miles. I decided to change it one day and WOW is all I have to say. It made a huge difference. My LET Z07 (60mm) HKS exhaust, RB header and presilencer and intake were the other major improvements.

Rotaryman88,

I would really like to clean my injectors as well. There's only one problem... to get to the secondaries, you need to remove the whole upper intake manifold to get to them, and I just don't have the tools to do that, nor the technical knowledge. In any case, MAKE SURE you clean you diffusers when you go and clean your injectors. I guarantee the little hole that's in the middle will be completely carbon clogged, and that can make a big difference in power when the secondaries come on-line.

RXSter,

Did you buy an aftermarket O2 sensor, or just a stock one from Mazda? I really think I should just throw mine out and buy a new one.

BUMP

1. ATF trick
2. Remove lower intake to clean.
3. Replace or remove cats.
4. Techron Fuel injector cleaner.
5. doing a 500 mile oil change (haven't tried this yet.)

BG 44k I heard good things about that

Um 500 mile oil change? What good is that supposed to do??? Just curious. And if your going to remove your lower intake to clean it, you might as well do the TB, upper intake, etc...lol. When we did James'(Wankel7's) '91 TII, we took all the intake parts(upper and lower manifold) and let them soak in both kerosene(mainly to get the stubborn gaskets off) and then in Simple Green(the best cleaning solution ever made...my opinion) to clean them up. It worked out well....

If you change your oil, then change it again 500 miles later, its supposed to flush your oil pan out. You know, clean up all that crud that gets left behind every 3k change.
I haven't tried the TB mod yet. I had the intake apart to fix my auxilary ports. It was pretty silty.