If I'm at 70 mph while in 2nd gear and trying to redline, I'll get a blinking CEL (misfire) at 7k rpm while my accelerator is on the floor, and the rpms will stop climbing and never get to the beep.

My 8 has been doing this for as long as I can remember, but after today's install of a new BHR coil/wire set, there's no more fixes left I can think of, I've been searching for months but have yet to find a definitive answer.


Here's a video I just took of it happening:
20120924 182357 - YouTube


Car info:
-2004 AT 105k miles original engine (half highway/city).
-Brand new BHR coils/wires, new NGK spark plugs
-Zero starting issues, always less than 1 second cold, smoothly idles typically at ~900-1,000.
-All maintenance kept up with well, 10w40 oil for the later half of its life, all sensors I can get to clean
-Redline once per day of course, and I drive it hard (for an AT )
-Compression was good at 99,500 mi (this issue still showed up long before that though).
-22-25 MPG, get up to 350mi on a tank.


Car drives 100% perfect other than that one specific situation. Last week the conditions were perfect enough that I even spun my tires for the first time in a straight line flooring it on a highway on-ramp (didn't know the 8 had that in her).

I have a bottle of zoom engine cleaner on order, which hasn't been done in a long time, so that's my next step but I don't suspect I have much carbon build up. The Cat seems fine too, but I guess it could use a more thorough inspection from an expert. Other than that, I'm at a loss!

 

What is the ohm rating on the wires Charles hooked you up with?

 

Did an engine clean with mazda's zoom cleaner. Also reset my NVRAM (20 brake press). Still didn't fix the problem.

Bummed all this time and $$ didn't do much...I'll be honest where most people say "it drives like new!", I noticed no noticeable change in regards to plugs/coils/wires(BHR), engine cleaning, etc. Though maybe that's a good thing, indicating things were already running optimally. Although there was one nice payoff, I saw a huge increase in MPG, I now get a stable 30+ MPG at low highway speeds (~55 mph), where before I never saw more than 22-24.

Didn't catch it sry, is it written on the wires?

 

Symptoms indicate an exhaust restriction - can you get a 'test pipe' loaner?

I hesitate to suggest you take the cat out and go for a spin, the noise would be literally painful. You could try loosening the cat to allow some gas out of the header/cat joint.

I have experienced clogged cats on other cars and this sounds classic.