Rx8 Loss of power

Rx8Bosnian

Member
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Mazda Rx8
I have a 2007 mazda rx8 automatic 6spd and recently ive been experiencing a loss in power. also i got my spark plugs, ignition coils, and wires replaced recently aswell. there is no cel whatsoever. although i should include that there was a p0420 about 4-5 months ago it came on for a week and my friend erased it when he was looking at what it was and it never came back on. i do i have a cold air intake(k&n) and i also got a muffler delete about 1 month ago. i notice my intake gets louder when it hits around 4,000-4,500. now i drove around and got live feed for my cat because thats what i thought was wrong and apparently the cat is fine. i was looking at the temperature and temperature goes around 1,700degrees when accelerating but drops down around 1,500 at normal cruise. if the cat was clogged i believe the temp would exceed these numbers, but i still havent ruled it out yet. Only thing else i can think of is compression loss. let me know your thoughts about this and if u need any info
 
K&N intake is not good and could be causing problems if it was not installed properly.

We're the plugs/coils/wires done before or after the power loss started?
 
K&N intake is not good and could be causing problems if it was not installed properly.

We're the plugs/coils/wires done before or after the power loss started?

I got 2 engine codes today p0411 secondary air injection incorrect flow detected and p0113 intake air temperature circuit high input. there was definently power loss before the sparks/coils/wires but it only got worse. let me know what you think
 
The secondary air DTC will not cause any drivability concerns.

The IAT DTC is your red flag. It's integrated into the MAF. A MAF concern would, obviously, cause power concerns, but you're not having a DTC for a MAF circuit, only the IAT circuit.

With the clip of the MAF sensor plug facing up, the terminals are as fololows:
[e|d|c|b|a]

Measure voltage between terminal d and ground- it should be battery voltage (b+)

BTW, your cat tempers are okay, though it's best to take a thermal gun and take an external pre-cat reading and an external post-cat temp to get an idea of variance. If you see 800 pre-cat, but 600 post-cat, you know you have a restriction. However, if you recorded a pre-cat temp of 800 and a post-cat temp of 750, you're okay, that's normal.

EDIT: If you can view live data on your O2 to get the operating temperature of the cat, you can view live data to view your actual intake air temperatures. Obviously, if it's -80F or 250F, your ECM is going to see that and adjust the fuel trims to an appropriate level to match the intake air temperatures.
 
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Ive already ordered full exhaust system with a high flow cat. I dont believe the air pump affects performance, its just there to pump exhaust air back to combustion to warm the cat up faster so if there is restriction in the cat itll be harder to pump the air and i believe thats what triggered the code, for the p0113 i put back my stock intake i believe the connection harness on my k&n was bad i didnt want to mix the 2 harness even though its really easy to swap them so i just replaced my intake for now. so once i get my cat replaced ill let u guys know if it fixed it or not
 
Ok so i fixed the problem and just because i hate when i have a problem and someone starts a thread with a problem similar to mine and doesnt finish the thread or states the problem ima go ahead and help out some people in the future in case this happens to you. so if u feel a loss of power, hesitation, hard to start when hot(sometimes cold), the first thing that should pop in your head is cat and thats what popped in my head. but looking at the temperature it seemed to run fine and yes that cat ended up being the problem, but i listened to some fellow rx8 owners and they told me ways to tell if its bad just by looking at it and NO it was not glowing in the dark, No rotten egg smell either. Im not saying this will not occur to your car im just saying if you have the slightest hint that it might be cat just by visual check is sometimes impossible to tell so i suggest just taking it off and looking at it. also when i took the cat off little chunks started falling out of the cat itself so yeah it was pretty bad...Well thats all, hope that helps anyone else in the future.

Also i installed a turboxs high flow and catback and its a freaking animal! love the sound. i definitely recommend it! Just hope i dont draw too many cops with that 13b coming to life again :]

So there you go thanks to all the helped and let me know if you have a similar problem
 
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