okay so heres the history:
got the car, noticed later some lack of power compared to my brothers rx8 from 2 years ago. 1st thing i did was get new coils, plugs and wires, cleaned the maf. saw some oil in the intake, cleaned that up.
few months later still there. then suspected the cat.
one day, i was driving hard, noticed it was getting toward hot, didnt completely over heat, got up to 3/4, naturally as soon as i saw it moving i put it in neutral
day later i got the cat removed and got the shop to install a pipe instead. so kinda like a test pipe. they couldnt remove my o2 sensor so we just unplugged it for now (no o2 senor where the cat used to be) on my back from there, i was driving hard again to see what difference it made, noticed the needle moving again, so i stopped again


Heres the problem

its been 2 weeks since then, and 2 days ago i noticed that my oil light came on.
checked the oil, it was fine. shut the car off, restart it, no light, few miles later randomly, came back on, its only solved by restarting the car.


lack of power is still there, although i stopped driving hard obviously, ussually drive like an old grandma now. the lack of power isnt that horrible, basically its at around 4500rpm. you feel a jerk, still revs up all the way, probably not as fast as other rx8s but still there.


any advice? is the engine about to go? what are my options?

car info:
2004 rx8, currently 80,591 miles. only mod that i know off is the aem intake and the decat. i also suspect that theres a leak when they welded it, ill get that fixed when i go back for the o2 sensor.

 

As for the overheating, check your coolant level. And are you sure it's the oil light that's coming on? Sounds to me like it could be your coolant level light. They do look similar after all. The oil level light on this car looks like an oil pressure light on a regular car. As for the power loss, it could be low-ish compression, but these other issues aren't related to that. Does it take long to start when warm? Is your check engine light on?

 

https://www.rx8club.com/newreply.php...eply&p=4520433
its the second one from top (this is just a picture for reference, got it online NOT MY CAR)

yup, checked the coolant, it was good. its definitely the oil light, its the same one like symbol on the oil pressure gauge. im looking to see if i get a compression test now. noticed it today again, it almost always between 4000-4300rpm to be specific.

not sure if relavent:
when i got the car, used to get 17-18mpg
then tune up, got 20mpg on the only fillup i did.
after that started using premix, got 17 mpg strictly
after cat, i get 15 mpgs from the past 2 fillups

also all oil changes were from mazda dealer. but they put 5w30 not 20 for some reason

 

Is the oil light coming on steady? or is it flashing?

Nothing you are saying yet really points to engine failure. The coolant temp needle moving upwards is a huge concern, and might lead to engine failure at any point, but it doesn't strictly mean that you have it yet, and it doesn't cause the rest of the problems.

Something is failing though...

 

by oil level being fine you mean it was at the top of the hashed area? if it was low in the hashed area the light will be delayed but still come on until it is topped off. if it is below the hashed area it will come on immediately and stay on.

for the temp issue make sure the car still has an undertay, the fans are working when the car is up to temp, the coolant is clean and topped off and then change the thermostat.

without the upstream O2 sensor the car won't be able to go into closed loop and will run rich and get poor fuel economy.

 

the oil light come stays on, no flashing. if i shut the car off, and start it back up, i get a 5-10 miles without it coming back on. im almost due for an oilchange so i guess ill just get that now and they'll top it off for sure.
the coolant is clean, well greenish as far as i can tell. i dont see it being darkish like my other cars were in the past.
oil level is in the middle. it was little under middle to be honest but not low low.
i understand that driving hard would make the car oil thirsty but how come it comes on even when i barely take it over 5k?


also the undertray has always been there, just damaged where it mounts to the bumper. i have zip ties on it. its always been like this ever since i had the car. never had that problem and ive driving in hard pretty often before when the car was new.

ill get the o2 fixed and see if that fixes the mpgs.
will an exhaust leak cause all this?

 

Ah, ok. Yeah, it's letting you know that your oil is low. High revs push more oil out of the pan and into the engine. If you are borderline low on oil, this can be enough to trigger the low level light at higher RPM.

You are topping it off regularly, right?

 

that is about where the light comes on. so its acting normally