Tonight while out driving around after the car was good and hot. From roughly 6k rpms and up the car breaks up. Obviously once realized what was happening I got out of it. AFR gauge showed rich when happening so it's not firing as it should.

What I know. .
Cars on MS3X and hasn't had an issue till tonight.
Below 5 to 6k WOT and normal driving the car does fine.. spark plugs are all heat range 9 and have 1k miles on them. Plug wires are at least 4 years old and appear to be in good shape.

I'll ohm the wires tomorrow, other then that and perhaps buying new plugs. What other tests should I run to check and hope it's not my coils giving out.

 

Is the car a TII or NA? This makes a big difference when diagnosing running issues.

Basic things to check without knowing which engine you have are the coils and injectors for proper resistance. You'll also want to ensure your engine bay grounding points are clean and secure. Hook a fuel pressure gauge up to the feed line and see if there is a fuel pressure drop at higher engine speeds. Check the air filter to make sure its not partially clogged and consider a new fuel filter if its not been replaced in some time. These are just some basic things to check.

 

Sorry thought it was in my post. TII

Turbo guard is clean and clear, fuel filter was replaced 4K miles ago. It’s still getting fuel, it’s rich misfires not lean.

Acts like an old turbo Honda when the igniter, spark plug or coil was failing. 10psi of boost 6k rpms 3rd gear starts breaking up. I will check fuel pressure this evening, and double check my grounds.

 

that's around peak torque. check plug condition and coils, recommend you switch to 10 heat range gapable plugs for tune-abiity rotor housing health.

 

Thank you, and what do you recommend starting plug gap to be?