Turbo Problem?

[osidemx5]

I have an 04 Mazdaspeed MX5 turbo, stock. It just started to have a problem at 3000 rpm. When you shift through the gears, everything is fine. When in 4th,5th, 6th at about 3000 rpm and attempt to accellerate, the car lugs and stumbles. Almost as if its not getting power or the power is retarded. It is also making a spinning or hissing sound as you accellerate. If you rev the motor while stationary it does not have this problem.

[Lanou]

After installing the Flyin Miata intake on my Mazdaspeed, started having the same problem after a few months. I found the problem to be the FM O2 signal modifier. I assumed that was not adjusted properly and cause the mixture to be too rich. I ended just unpluging it has it didn't seem to make any difference anyway.