I may have a bad cat......
 

Hey Guys,
Ive only ever been in my own Rx8 so I'm not sure if this is actually a problem or not... Anyway, when I absolutely floor it in first, the car seems to get up to about 7K and then it feels like its only slowly inching forward up to the 8.5Krpm and in 2ng gear it makes it up to about 7.5rpm and almost seems like it wont go any faster so there no point in taking it up to 8500. I mean from what Ive read, if you want to feel the power of the thing, you need to take it up to 9K. But by the time I hit around 7K it feels like it really pick almost no more power in the next 2Krpm. It just sounds like the engine is screaming and I'm scared Im gonna get a check engine light flashing at me because the engine screaming, yet Im hardly going any faster... Can anyone shed some light on this?

Thanks so much!

!!UPDATE!!
For those of you who have been following along and helping me through this...
Yesterday I installed my new plugs coils and wires, and the car ran just the same as it did with the old plugs coils and wires... It made no difference. What happens is the car will pull up to about 6000 rpm and then it will have a delay and then pull again to where it struggles to reach 7500 rpm and at 7500 it just will not go any further :( It almost sounds as if its hitting a rev limiter, but its no different between first gear and 2nd gear, the car cannot push past 7500 rpm.

So now its time for the last resort, take it to the dealer :(
This dealership has screwed me over before and I know there not going to be pleasant to deal with when it comes to doing any warranty work for possibly the cat or loss of compression. Can you guys offer any advice that might help me when dealing with the dealership that hasn't been very honest with me in the past??

Thanks guys!!!

Peak torque ends around 5500 rpm (stock tune), but peak power happens at 8500 rpm.

if you're getting a lot of blinking CELs, you might want to check your coils, plugs, and wires.

we want more details.
when did you replace the plugs and coils?
what gas do you use?
any check engine light?

Ive only ever got a flashing check engine light once, I pulled over, turned the car off, turned it back on and no light. So it seemed like nothing. About a month ago I got a check engine light for rear O2 sensor, and from what Ive read, its next to useless so i havent been in any rush to fix that yet. I have always used 5-20 oil. Always used premium fuel. never replaces plugs or coils, Ive only owned the car for one year. its a 2005 manual GT

I just read another thread where the person talked about being able to start the engine when cold just fine, but when the engine is hot it has trouble starting. I am having that problem as well... I can drive one block turn it off cold and it will turn back on completely fine. But when I turn it off hot and try to start it again right away, sometimes it will struggle, so much so that sometimes the needle on the gauge will even reset.

Any advice is greatly appreciated!

if coils and plugs are new, chances are you engine is going bad.

Dying catalytic converter. Happened to me with exact symptoms like yours

Is your car still under warranty? If your car is an 05, then it should fall under the warranty, if the problem is the engine. Bring it to the dealer and have them check it out.

How would I be able to tell the condition of the coils and plugs? and what are the symptoms of a dying catalytic converter? Is the catalytic converter covered under the 8 year warranty? and yes it is an 05, but its already had a new engine put in, does that mean the warranty is over if they have already replace my engine once?

pull the plugs and look at them. the cat is covered under warranty. and you can get that engine replaced too as long as you're under 100k miles

How would I know if thats Cats gone bad? and that CEL for the rear O2 sensor keeps turning on and off daily, so whats your take on that?

If your getting a check engine light change ur O2 sensor...as for a dying cat syptoms might be ur car turning off on u here and there...also drive it around at night time then leave ur car running get out and look under ur car at the cat to see if its glowing red.

but by what ur saying most likely its ur engine starting to go wrong. Take it to the dealer and get a compression test. They'll let u know if u need a new engine, and if so ur covered under warrenty :-)

Thanks so much guys!

Get the dealer to remove the front of the midpipe and take a look inside. If you are lucky the cat honeycomb would visually show cracks or sign of deterioration. If you are unlucky like me, you get no obvious symptoms at all, no glowing cat, no rotten egg smell, no CEL , only thing i got was car started to overheat when i kept pushing the engine in the 7k rpm range uphill.

bump

why are you bumping?
Can you shed some details as to what you have done to troubleshoot? Have you checked everything that the others have mentioned?? If so, what was the outcome?

clogged primary cat ... we have 2 cat elements ... the secondary o2 sensor goes in between them ... it probably gets VERY hot ... like glowing red hot

solution:
1. get another cat ... they pop up in FS once in a while for a good price
2. get this http://www.racingbeat.com/RX8/Exhaus...nts/16221.html or http://blackhaloracing.com/?page_id=...&product_id=21 and SHOOT FLAMES ... and smell bad

The CEL for the rear O2 sensor is intermittent turning on and off about once a day, and even if it wasnt I wouldnt be too worried about it. I will be installing the NGK Laser Iridium spark plugs along with wires and coils when they arrive this week and Im hoping that will take care of the loss of power at the high rpms. and I'm still looking for a place to get a cheap rear O2 sensor as Im guessing that should fix the CEL P0139

Thanks guys

My bet is on a bad or dying cat.

Why would you say cat? What are the symptoms?

I really need help :(
 

Hey guys.

I'm in need of some help and I figured you guys know the rx-8 better than anyone else... Kinda got two issues going on right now...
1. CEL P0139 turns on and off usually at least once a day... (P0139 = Rear HO2S Circuit Slow Response)
2. Lose power at 7K RPM and cant get much higher.
3. (not a big deal) Car starts fine when cold, but sometimes takes a little while to turn over when hot.

From researching this website many have said the solution to this loss of power is to replace plugs, wires and coils so I have order the NGK Laser Iridium Plugs and NGK coils and plugs. They should be arriving this weekend and I'm really hoping that will take care of the loss of power. My CarMD told me that replacing rear O2 sensor is the most likely fix for my CEL P0139. So I am in the process of finding a replacement 02 sensor for the best price I can.

Advise:
So Ive been hearing different things from different forum member and Im really confused and would like some help before I keep throwing money out the window on fixes that may be completely irrelevant.
1. Ive been told that it sounds like my engine compression could be going which means time for a new engine, but before I go and pay for a test, I should replace the plugs coils and wires, which is what I'm in the process of doing right now.
2. Ive also been told that its sounds like I could have a bad Cat. (If it was a bad cat, wouldn't my CEL stay on and not turn on and off daily?)

Is there anyway for me to determine for sure what the problem is with my car regarding the issues I have mentioned? And also how to fix them? Im an 18 year old and cant afford to throw out money for possible fixes that may be completely irrelevant, so whatever help you guys can give me would be extremely appreciated!!!

Thanks so much!!!
Brandon

theres a thread somewhere in the forum with all the engine codes and what they mean so you can find some info there. Also it definetly sounds like a bad cat (maybe its time to get a midpipe lol) and if the car takes a long time to start when hot it might be low compression so you can take your car to the dealer and ask for a compression test, it should be about $100. If your car fails the test you can qualify for a new engine under warranty if you still have it. You might need to provide some oil change records but some dealers dont ask for it. They might also ask you to get new sparkplugs, coils, and wires and then do the test again.

Thanks for the response. How would I be able to tell if the Cat is bad? what is a mid pipe and why would I need to get it?

Sorry guys I dont know much about cars :(