2004 rx8 6-sp was running fine 2 days ago when i went to drive to the store yesterday it wouldn't go above 3500rpms i thought it was in limp mode but i am not sure because when i start it and give it some gas it will redline but after i take my foot off the gas and try it again it wont rev past 4500. I checked the coils and found that one had no spark so i replaced it and still nothing. I don't want to gut the cat unless i know thats what it is and if i do gut it will it put it or keep it in limp mode. I had advance auto read the cel and all i had was 2 small leak evap codes.Won't be able to check compression till tomorrow but i don't think the motor is bad because it starts up just fine and when idling its fine. I have searched threads all over the internet but its really useless due to the fact can never find what the hell your looking for. Any input would be great

 

Who ever can give me a correct answer i'll give em a sticker

 

The compression in my motor is low and it idles fine and starts up fine when cold.


The first thing I would check is the CAT, if your under 80,000 miles its still covered. If that checks out then get a compression check. How many miles on the coils & other plugs?

 

15k on plugs and wire don't know about coils car has 102k on it i got it at 85k. Also it starts fine when its hot too. If the cat was clogged would it set a code for it. See where i am confused is its f-ed up but there a no codes to even go by

 

The starting fine when hot is a good sign. I don't have a CAT and I do not have any CEL's, that happens with some 2004's. That means you could still have a CAT issue and your symptoms lead me to think its that. The price Mazda will charge for a new CAT will shock you so if its that you might want to go with a midpipe or a non Mazda CAT.

 

i figured they would rape me on a new cat i just jacked up the car i am going to take the cat off to see if that will allow it to open up

 

There is a certain way to remove the CAT, its been on for a while and will not come of that easy. The thread below will be of some help.

https://www.rx8club.com/series-i-do-yourself-forum-73/diy-racing-beat-resonated-midpipe-install-194450/

 

thanks i got all the bolts off the cat now just the o2's and the brackets are left

 

I hope the cat is the problem i could then convince the wife to let me get a new exhaust

 

didn't work

 

how about the omp if i disconnect it what will that do i just looked at it and one of the wires were cut off hopefully it just happened

 

A v-tec or dohc sticker