I'm having a weird problem on my AP1 S2K. When going full throttle in any gear, the car will only reach about 8600rpm before cutting out. It does not sound like it is hitting the rev limiter, it makes a sound similar to trying to hit vtec before the engine is fully warmed up (Last time I let a woman drive my car). But anyways under about 8k rpm, the car drives completely fine and feels normal, hits vtec normal etc., but after 8k, the torque falls flat on it's face before hitting 8600 where it completely cuts out. I have a check engine light for the primary O2 sensor heater and will be replacing it soon, however I think this is unrelated. The car is stock except for a Berk HFC. I recently did a valve adjustment prior to noticing the issue, and I think this could be the culprit but I checked the clearances and they seem to be okay. I recently had a local shop test the fuel pressure all the way up to 8600 and they told me it was very good. Does anyone know what this could possibly be? I think my best bet is to have a professional adjust the valves for me, but I thought It'd be best to ask around here first. Thanks in advance!

 

Status of spark plugs? Air filter? Do a compression test?

 

The spark plugs have about 40k on them and are OEM NGKs, but the coils are original. The car is at just about 175k miles. The air filter is OEM and was changed about a year ago, probably only has around 5k miles on it. I'll swing through harbor freight when I get a chance and pick up a compression tester. I'll post back with results!