CEL w/ coughing and sputtering
 

Ok, so...

I have a CEL and i'm trying to figure out what it could possibly be. Usually when i've had a CEL the car doesn't even act up and it ends up being nothing and when the car acts up it doesn't throw a CEL... funny how that works out like that...

Anyways,

Car:
04 RX8 GT MT
48000 miles
No engine mods

Symptoms:
CEL kicked in on start-up
Occasional sputtering during acceleration
Burnt smell from under the hood

Recent Activity:
So it's been snowing a lot here in the Northwest but i managed to make it home to my parents places for x-mas. I left my car parked outside for 4 nights (it's usually garaged) and didn't run it because it wasn't THAT cold outside and i had no reason to go anywhere in it. On Saturday we had to re-arrange cars so i started it, let it run for a while, shoveled some snow, moved it, let it finish warming up, revved it a few times then shut it off. When i was shoveling snow around it i noticed that the exhaust was quite smelly. I can't be certain if it was worse than normal i just remember thinking "FOR THE LOVE OF GOD, PLEASE!!!" Other than that, all was normal.

Sunday, I installed my AFE Short Shifter, which is awesome BTW. About two hours later it was time for me to leave so i started it up and it immediately threw a CEL. I didn't think much of it at the time but i was hoping it was nothing major and went on my merry way. The car was fully warmed up and i went to accelerate on to my first 55 mph road and it hesitated, coughed, stuttered through 2nd gear. I ease up but continue. I drive mildly until i get to the freeway where i have to give it some gas again. Once again it stutters and coughs through 2nd gear and a little into third.

I got off the freeway about 30 miles down the road and got back on. The car hesitated, but not nearly as bad as before. It might have been in my head it was so subtle. Cruising a long at 60 there were zero problems.

Close to the end of my 100 mile drive i had an open junction on ramp and i decided to see if it was still acting up so i hit the gas. Gradually, but it did hit the floor. The car ripped through 2nd gear no problems at all. I was actually quite impressed with the pull.

When i got back home and in my garage i smelled burning. It almost smelled like burnt rubber but i have a feeling it was some oil i spilled out of the filter on my last oil change based on where the smell was concentrated.

That's all i've got. Any thoughts? Coils? CAT? Neglect?

I'm going to drive it into work tomorrow morning and see if i'm still having issues or a CEL. I'll probably take it in to get checked out if i'm still having issues unless you have any suggestions.

I say cat. I'd get the code read, then you will know for sure.

Probably won't hurt to change the coils, especially if they are original. I see your getting the BHR Ignition though.

Cat eh? I seem to remember reading something about how by law a cat has to last some 8 years or 80k. Am i remembering this correct? If not, i'm always down for the RP Super Cat. If you buy a performance part as part of regular maintenance it's not wasting money right ;) i.e. coils go out = BHR Ignition, Cat goes out = RP Super Cat, Clutch dies =... etc etc etc :)

yeah, should be covered under warranty

So i drove to work, still had a CEL but no real apparent issues. I think it may have hesitated once around 4.5-5k in 2nd gear but not sure.

So i called Mazda to get an appointment and they could take me right away. So i go start up the car to drive there and, of course, no CEL. I drove it around a bit and there were no obvious problems.

Am i safe? It seems like if it was the cat i would still have a CEL. I am getting the BHR ignition as soon as my name comes up on the wait list, so if it is the coils i should have that problem fixed soon. If it is the cat or something else i guess i'll just wait for it to come up again.

Its the Coils!!
 

I just had 3 of the four coils replaced on my very early 04.
Had the same symptoms including the smell. Apparently it doesn't throw a CEL until both coils (leading and trailing)go out in same rotor. I had been noticing an occasional drop in power and slow starting. Was not covered under warrantee and the parts cost ~$35 each
Get them replaced before it fries the cat.
Bob D
Mission Viejo CA