so im having some problems with my 8, the car sounds like it has vtec at about 4000 or 5000 rpm it starts making a really loud noise(i have the K&N typhoon) like the way it sounded when i revved up to 7K before when it was running good and as that loud noise comes on the car seams to run really sluggish even if i am flooring the throttle, after a hwy drive once the car is at a stand still it idles really rough......i replaced coils wires and spark plugs and still acting up throttle body also replaced

has anyone had this issue before??? any ideas??? some people where saying it could be a cat that was clogged but after running for long periods of time cat are not red like if they where clogged...

i had it checked out by the dealership but they told me nothing...and charged me a $110.

i did hook it up to the obd 2 and it gave me a code saying throttle position sensor high voltage bit i could not find anything on that.............
oh FYI(04 with 110K)
thanks for the help

 

Power loss and rattling are popular discussion

https://www.rx8club.com/series-i-trouble-shooting-95/noise-loss-power-202296/
https://www.rx8club.com/series-i-trouble-shooting-95/loss-power-rattle-help-201332/

Lots of discussion about this issue... No solutions but lots to check...

 

hahaha, seems like tons of people are having the same issue.

 

I double checked all my wires today, they're all good. Went for a drive, no problems as usual..... it's so intermittent!

 

"Sounds like vtec..."

 

If he claims it drives like a v-tech then I would start to worry.

 

it is random sometimes when it is cold out and i go for a drive the car is fine reves nice, pulls hard, drives good but after a while like 30 min when your driving normal and you hit the 4k to 5k rpm mark the car sounds like it is taking way to much air trough the intake and then it starts running sluggish. it feels like it wants go go faster but then something is holding back idk it could be something to do with fuel.......do you have any suggestions about something like a sensor or something that once it heats up it could cause this???

i used a obd2 and got a throttle position sensor reading high voltage but i could not find anything about a throttle position sensor.......any ideas on what that can be???

 

The TPS relays info to the ECU. If the TPS is malfunctioning then it could be the ECU is not delivering correct amounts of fuel through the injectors. Due to a wrong TPS reading. Leaning or richening the fuel system out relative to the TPS position setting info it is receiving.

 

GEt rid of that pice of crap KN intake.

That is your problem.

Search and you will find out.

 

this. The temperature of the air going into your engine matters! The K&N sounds good but has been shown to produce lower HP numbers than the stock intake. If you still have the stock intake, put it back and see what happens

 

In the next couple of weeks I am going to just break down and pull the panel to take a photo of the stock VFAD system. That way I can just show people how retarded it is to pull air from the engine compartment vs the fresh air that pulled from the front of the car.

 

i do have the stock air box ill install it tomorrow and see what happens ill see if that fixes it......thanks guys for all your input

 

so i final got a chance to put the stock box back on and well it stopped the (loud)noise the loss of power was there, so i didnt know what else to try i had to drive my dad to an appointment out of town about 90 miles away and on the way there it drove sluggish on the way back idk why but it came to me that maybe a fuel injector was clogged or something because between 75mph to 85mph it would not pick up any higher then that even flooring it. so once i got there i when to the local o'raily and bout a chevron fuel filter cleaner treats 12 gallons they had a sale buy one get one free lol so i bought it pumped gas(full tank) then began to drive back......

about 1/4 ways back i began to be able to pass cars on the freeway =) haha the car would accelerate from 85 to 100mph in no time at all so after all that time and money i guess one of the fuel injectors was clogged or something its been 3 days now and the car is running strong still i think that did the trick!!

thanks guys for all your help and advice

 

I had the same problem and I took off my K&N intake and never looked back.