I've replaced pipes, MAFs, solenoids, even the turbo

And still we have "good days" and "bad days"

Even the main stealers have found it baffling.
So yesterday it was running particularly poorly whilst out on a run to the point where it was an embarrassment to drive it, a mik float actually had more power

So I knocked the engine off at a set of lights and restarted it, which usually clears it for a bit. Firstly I noticed for the first time an odd whistle.
When I say odd I don't mean the familiar turbo whistle, I'd never heard whatever this is.
I was baffled and put it down the the window being open.
However, I got home and as the car had run pathetically I popped the bonnet a couple of minutes after switching off, mainly to see how much of a pig it was going to be to get the EGR off.
Whilst I was stood there there was what I can only describe as a funny noise like an old kettle whistling for about 5 seconds which tailed off.
The funny thing is, the car is now flying. And when I say flying, I mean keeping up with a Celica last night

Did I broked it or is there a more suitable explanation for it?
