I have 04 MT RX8 with 50k miles (this happened randomly-i drove 10 miles stopped car and was fine, then drove back 10 miles car was fine, and then next time i turned on car i had following problems)

-Barely revs past 7k then it stutters up to 8k at max

-Very slow revs going up to 7

-New spark plugs

-Oil Level Fine

-Coolant Level Fine

-Just put stock cat on

-Car starts up normally

What could be the problem?

 

coils first.

plug wires not tight second.

cat, but you said you put that back on. confused about that.

fuel pump third.

beers

 

i put cat back on after using turbo xs midpipe...just to see if possibility of a clogged cat

 

you had the problem with the turbo xs midepipe? if so you can remove the cat midpipe from the problem..

beers

 

no i had problem with midpipe (it was to loud) so i put on stock cat

 

maybe the ecu made itself a learned file for the midpipe, and now with the cat on it has to relearn the new set-up. that is if the only thing changed was the cat. put back on the midpipe and see if it goes away. good luck.

 

was the loss of power after you put the cat back on?

beers

 

yea but a about 2 weeks afters

 

put the mid pipe back in and see if it revs again.

you killed the cat..

beers

 

If its not the cat then I'm almost 100% sure its the coils.

 

Yeah, sounds like it might be plugs & coils time

 

I would try coils too.

 

if you end up having bad plugs and coils you may have killed you cat aswell, so check that while your at it

 

def sounds like a clogged cat,

put the midpipe back on and if your car seems normal, you found your problem.

 

i put the pipe n but now the car wont start...but the cat was clogged

 

any1

 

so your car won't start...? is that the issue at hand here? the other issue was solved...being a clogged cat, correct?

 

It's probably flooded now. Try the deflood procedure in the manual.

If that doesn't work, you can push/pull start it. Be in 2nd with clutch in at about 18mph, then let the clutch out smoothly. If it starts, put clutch back in and go to neutral(don't let it stall). Stay like that a minute or two, then go take for a spirited drive. If you can't do that for some reason........

you can start pulling plugs, cleaning them, purging gas/oil out of the engine by pulling the fuel pump relay and cranking the car 10 seconds at at time, with 20 seconds rest in between, until all smoke and liquid doesn't come out of the plug holes. Then re-install plugs and crank it over. Once it catches, have someone plug in the fuel relay will quick. If it doesn't work....then start over. Oh yeah.......you better have a spare battery as this will kill a battery quickly.

 

^^^ Sounds like fun, Im lucky I havent flooded mine yet from the sounds of it

 

great success deflooding FTW

 

so how does it drive now?

 

Update.

 

drives fine...i had to put midpipe back on and its sooo loud

 

list it FS + oem trade.

 

Glad you got it running! What was the method of choice......since there is at least 4 ways to attempt it?
I've never flooded mine, but I have deflooded an Automatic for someone.