Ahh, I was so close to popping off the negative terminal to reset the ECU, but left it as I didn't have any warning lights. I'll do that when I come to fitting the new pipes and check over the spark plugs.
The guilt pipe was the 90 degree coming off the throttle body. Such a shame as it was pulling like a rocket.
Have a few jobs to tackle this week/weekend before the Basingstoke meet on the 2nd:
Sort dash illumination issue - 10amp fuses keep blowing.
Replace rad cap, bleed water coolant and investigate why the expansion tank return pipe is blowing air into the tank, pressurising the tank.
Replace boost hoses.
Oil and filter change.