It seams to be the rev limiter. I checked the the under dash grounds there good. Oil and coolant is good. Changed cpu# 2 next step changes gage. Any other ideas out there ?

 

Sounds like a sensor or the wiring harness if you have changed the CPU. So you have a parts car? What's the harness like? If it's good pull it out clean it up make sure it is spot on and try it. My money's on rats hit harness, someone probably did To many poorly done mods

 

No rats and only "mod" is a 2 way alarm. I am going to try a new set of Gages next week and if not will look at Harness which is not that easy to change in the fd

 

Did you ever resolve this? I have a continuous beeping that only seems to happen when the car is sitting in the sun, in the shade it doesn't do it...
I know I recently removed the seats and messed around with CPU #2 on driver footwell.

 

Just dealt with this same exact issue, after some trial and error it turned out to be the speedometer and not the tach or cpu. Note, I also had to replace the ecu at the same time.

You car may have been exposed to something high voltage/current related like being welded on or lightning bolt hitting the car.