Recently my car started cutting out/losing power at high rpm when it is just warmed up. Later when it is fully warmed up this dissappears. I thought it might be detonation, but the PFC shows very low knock (20s) which is normal, AFR is 10.5 or less, and boost is 15psi. I recently swapped to all 9 plugs. Any ideas?

 

What plugs were you running before? It might be an ignition related problem--coils, plug wires, plugs. What brand wires are you running? I had Taylor Spiro Pros and they failed after about a year, and I've been told the Jacobs wires are **** as well.

 

ngk 7s/9s (P). found 4 copper 9s at pep boys locally while my platinum 9s were being shipped by RP. I couldn't see to know if it was half a turn or not, and I couldn't get a torque wrench in there, so I have no idea if they are torqued correctly-just finger tight and then a bit after that. stock mazda wires, but less than 6K on the wires and only about 500 miles on the coppers. Doesn't happen after it's fully warm. I still have a bonez cat without airpump. Could it be the cat?