Any smart ones out there? Have a 2006 WRX that pulls cylinder misfire for 1,2,3 and 4 but ONLY when the tach reaches around 3750 RPM. Regardless of which gear you are in. You can reach 3600 and back off without pulling a CEL. If you try to work through it the tach flutters at 3750 and higher. A CEL will flash and then go out. If you continue driving at those RPM the light will continue to flash and EVENTUALLY set and the "cruise" light will then flash until you clear the ECU.
The process will repeat again at 3750 RPM.
Yes, this will happen if you rev to 3750 standing still.
In addition, the tach will misfire (flutter) at any RPM over 3750.
Checked: timing marks, changed crank sensor, changed plugs, swapped coil packs, and yes 3 full tanks of premium gas. Only swap was someone put a 2004 down pipe and cats. Up pipe is stock as well as the turbo.
** No other codes except an occasional "Emissions pressure sensor voltage high**
Any help would be appreciated!!