Hi I'm new to the forum, I hope you can help me please, I have an 04 rx8 230 which has a misfire and runs rough, it had a full engine rebuild last year, I have put a new cat on, it has new plugs and leads, new coils, yet still each time it has had one of these replaced and the management system rest, after about 20 miles and fully warmed up it starts to miss at low revs and runs rough when I try to accellerate, I am at a total loss what it could be now as I have had everythingchanged one at a time, each time it seams to make difference for just a short time and then the problem reapears HELP PLEASE !!!!!

 

Did you have a compression test done before you bought the car?
How low was it?

Also, have you reset the ESS Profile?

BC.

 

I have an 04 too and had the problem last yr but mine was due to low compression. My car is currently out of commission and had the motor replaced and cat along with several other parts. I just found out today that my car runs great and everything is new but cylinder has a misfire???? So now I'm just waiting to see what's going on. But I did read misfire could be due to low compression, Cat, coils, plugs, wires, pump, maf sensor...It's unbelievable how much problems the 04s go through

 

Reset the ESS....then see if it gets better. I've seen replaced engines where the dealer forgot to do it...

check the coils/wires/plugs again....it isn't impossible to have a bad coil out of the box

Then you have to start SYSTEMATICALLY checking everything ignition and Fuel related until you find it....could be hundreds of things....from wiring to ECU...so you have to start from square one and check EVERYTHING

Oh....did you get a compression test?

 

Thanks for your replies, engine was only fully rebuilt by a rotary specialist 12 months ago and has only done 4000 miles so can't see it being compression but will get it looked at, also problem only occurs when it's properly warmed up which to me suggest an electrical breakdown when hot but coils have been replaced along with leads and plugs, is there something else I'm overlooking that might be obvious ?? Thanks

 

just a quick one on this, as the problem only appears when its up to temperature, has anyone ever experianced the temp sensor playing up and causing it to run rough as if the choke is stuck on ?

 

its possible, but it should throw a code for the sensor, or system too hot/cold

i would reset the NVRAM, the 20 brake pedal pumps, and if it still does it, compression. if compression is ok, put a timing light on it, and make sure all 4 coils are firing, then maybe clean the maf?

in any sort of problem solving/troubleshooting scenario, you start with the basics first

 

Hi thanks for everyone's help, problem now seems to be solved.
This is what I did if it helps anyone with same problem :-
Diagnostic said fault on cylinder 1 so changed plugs and changed leads and also coils, fault still persisted so did NVRAM reset, fault still persisted so then ridid NVRAM set plus removed 'room' fuse for a few minutes from passenger side (uk car)small fuse box hidden by a kick pannel, this appears to reset everything, result being car now seems to run smoothly without any missfire :-))

 

A search here may have brought you to my thread as in my signature. But glad you worked it out!

 

I have a 2008 Rx8 Automatic transmission
I bought it 4 months ago with 132,000 miles on it
It had a new motor put in with new plugs, plug wires, coils, and motor mounts.

About 1 month after the purchase started noticing performance problems and trouble idling also hesitations all the way through the RPM band then got an error code P04220 I believe.
Dealer said catalytic converter was bad. Dealer wanted like $1600.00
I told them no I would not have them replace it that i would take car of it.
I garaged it for a week while my Racing beat Dual resonated midpipe came in.

I put the midpipe on and now i am recieving errors for misfires and too rich/too lean.

I took it back to the dealer and they are telling me i need to put the stock cat back on and they will do it for $1600.
and that the lack of backpressure was causing my problem.

I do not think its the cat causing me these problems maybe it never was.
I have seen these cars with ehausts on them before. Also i cannot find anyone else having these issues with any aftermarket exhaust online.

I also have screenshots from OBD 2 tool for various bits of info ( although i dont know what i am looking for ).
Any thoughts or opinions would be appreciated.

 

I have a 04 rx8 that I have replaced everthing I can think of and still no fire only thing I haven't replaced is coils because I'm not getting fir to none of the four can all four of my coils fail at once any info would be great I've put all four coils on volt netter and getting nothing

 

is your ess disconnected or damaged? any fuses blown?

 

Where do I locate ess and no checked all fuses there good

 

looking at front of engine its the bottom most pulley (biggest) "crank" pulley under it in about the 4 o clock position. its held in place by one 10mm bolt and a wiring harness is attached to it. after its cleaned do the 20 brake stomp

 

 

... and?

You've already posted this in your other thread.

 

Apologies