I noticed a problem on my way to work today. On the highway my car was misfiring or breaking up at about half throttle. Let off the gas a tad it stops, give it a little gas it stops. Does the same at idle. I'll rev it about to 6k and it breaks up. It starts up fine (cold or hot), runs fine besides this problem. A few mods I have: BHR Ignition, pretty new, maybe 1,000 miles. Spark plugs and wires all new with BHR. Mazdaspeed CAI, Magnaflow hi-flow cat, ExoticSpeed exhaust. I searched, but I'll be honest, I don't exactly what to search for. Its an 04 6MT with about 58,000 miles. Original engine.

 

Do you have any method of viewing ODB2 data?

Perhaps a vacuum leak?

 

I'm sure I could figure something out...I work at car dealership, so I'll talk to one of the techs

 

if you can take some data logs of when it's happening, or at least pull freeze frame data and a log at idle, we might be able to point you to the problem, or at least rule out other options.

Most misfires are ignition, but it doesn't appear that will be your issue.

 

^ are coils/wires sometimes faulty from the factory? like a lightbulb? lol.