So, about three weeks ago i got an oil change and they told me that they ran out of the oil they need for my car and that i should put some more in at a later time, then i went about a week without putting any oil in it, right before a long drive to the next city i put in two quarts of oil which i guess was too much so it flooded out my intake and i only realized this about 70 miles after i put in the oil when i stopped for gas there was the slightest bit of smoke coming out of my engine bay, being in the next city i had no where to work on my car so i drove it back, another 70 miles, the symptoms were that at about 6500 RPM i had a massive amount of power loss, i was struggling to hit 60MPH in second gear but i could easily get up to highway speed by up shifting and keeping the revvs lower. so when i got back home i took an oil measurement and noticed it was above the point where the tip of the dip stick curves back over to the flat longer part connected to the loop, so i came on rx8club and tried to find an answer and by browsing what i got was that i needed to clean the exxcess oil out of my intake and clean my MAF.. so i took out the airbox, got a brand new K&N air filter. and reached way in there and wiped out all the oil best i could, then i took out the MAF and cleaned it with proper MAF cleaning solution. So after test driving it i noticed that the power still dropped at around 6.5k rpm and got worse the higher the RPM. so the next day i bought seafoam, and called up one of my budds to come help me clean out my engine, but he couldnt come untill the day after. So, having no other option i drove my car around to work and such, later that night i was chilling with some of my friends who also own and are very into sports cars.. we went driving around the outskirts of my city, nothing reckless just an easy laid back drive, when we merged into a highway and i noticed that my power seemed to be back at all RPM's and it was like that up untill after i seafoamed it. which seemed to only make it worse and now has less power at high RPMs than before. even though the night before it was fixed.

so i dont know what to do anymore, im a big DIY guy when it comes to my car b/c i want to learn more about it, any one have any tips or solutions? I was considering going cat-less and running a straight pipe, that might have something to do with it but again, i really dont know, any advice would be greatly appreciated.

My car is an 04 Rx8 6 speed manual GT with roughly 72,000 miles on it

 

Also, i forgot to add, that after the seafoam my Check Engine light came on and has not gone off since, that was about.. 4 hours ago..

 

After reading your post I suggest you take your car to the dealership. Fisrt who just adds 2 qts of oil without checking the dipstick first. Secondly, even after you noticed your car smoking you still drove in high rpms. How did you use the seafoam? What is the CEL code?

 

come back with the code and we can help you better

 

Well on the way back i didnt drive it at high RPM's it was just an observation that it had a lack of power, i took it slow and parked it at my house first thing, and for the seafoam i followed this thread https://www.rx8club.com/series-i-do-yourself-forum-73/diy-mazda-zoom-power-engine-cleaner-engine-cleaning-seaform-142852/
and yeah i know it was dumb to put that much oil in, but because after the oil change they told me that it was still low on oil, i found out now that they put in 4 quarts and the mechanic thought it held more so he told me the dip stick would be about 1/4 past the safe line so after a few days i put in two quarts, taking his word for it, but im not making excuses i know i fucked up but thats not what i was asking

 

Ok ill post the code tomorrow ASAP, thanks for helping

 

4 quarts in already and you put another 2 quarts? thats WAY too much.

before you take your car into dealership I strongly suggest you to drain your oil and refill it at proper level. or else if they see it being way overfilled they can and they most likely will deny any Engine warranty.

 

I drained my oil and filled it with the proper amount at the same time as i put in a new air filter and cleaned out the MAF and the air box.. and yeah i know its waay too much, but like i said, i honestly thought it was a lot less. Def. should have checked it though.

 

and your problem sound like engine going south.

it could be CAT clogging up too, but my bet is on the engine.

 

What else would tip them off to void my warranty? My oil level is fine now.. anything else i should think about?

 

prepare to show them receipts of oil changes and maintenance record like coils/plugs/wires.

 

aight, well thank you for the help, ill get back to you tomorrow with the codes

 

dont assume on the engine yet. a clogged cat and shot coils can seem the same due to the excessive backpressure. in fact people here have had engines replaced and when they reused the old coils and cat, no change in the problem. just unbolt the cat and take a look inside, should tell you everything you need to know

 

oh. haha seems like i have a lot to do tomorow, thats great to hear thank you ill definitely check that out tomorrow.. but a quick question.. will it void my warranty to do that? how about getting a straight pipe? also if its not the coils.. could it just be the spark plugs? if i am correct .. don't ALL the spark plugs go off right around 6.5k and beyond as opposed to less at lower RPMS? could it be that at 6.5k rpms the rest of the plugs aren't going off? maybe clogged with oil or something?

 

Basically the plugs fire all the time when the car is running...so that theory is out the window

There is an intake valve that open around there....check the code to see what it is

Did you check the intake tubes and clean them...if you didn't your MAF likely got oiled again

 

rarely will the plugs or wires fail before the coils in the RX8

 

Im sensing stuck SSV and clogged cat.
could also be MAF still dirty.

 

im sorry im not sure i understand what that means haha, and, the thing is that i replaced the coils not too long ago.. like.. 4k miles ish. i haven't had the car that long. i think less than 10k miles.. a few months

 

ok.. well ill double check the MAF although i doubt its still dirty b/c after i cleaned it, it fixed a rough idle problem my car had since i bought it, uhm, and ill research what an SSV is.. how could i unclog the cat? would running a straight pipe void my engine warranty?

 

you either get a new cat or just gut out this one so you have not cat.
running straight pipe should not but Ive seen some dealer might avoid the warranty.
get the codes pulled for free and if its the cat, I believe the car comes with a 8 year emission warranty so you might get a new cat.

 

NOW THATS USING YOUR DIPSTICK.. JIMMY...

 

So today i went and got the codes they gave me p0335 and p0302 one was in active i think the p0302 but it still read it, also i went to the Mazda dealership to ask them about my warranty, and if i remove my cat it will void my warranty.. but if thats the problem, can i just remove the cat, put a straight pipe and keep the old one and put it back in if i need to go in to the dealership?

 

you need to reset your timing, (20 pumps of the brake pedal) after you clean your e position sensor. if its still misfireing after that your cat may still be toast.

read here

https://www.rx8club.com/series-i-trouble-shooting-95/p0335-eccentric-shaft-position-sensor-circuit-problem-car-will-not-idle-194505/

 

you can remove your CAT. it will just void your emission warranty (and federal Law).

but to avoid commotions yes you can keep the CAT and put them on only if you have to visit a dealership.

 

removing the cat wont void the engine warranty, which it really all you have left