Whats your thoughts on this?

[Steve Burnett]

As some may know, I had a problem with my heat light flickering on and off. (I do not have an Apexi PFC so it was not knocking)

I got a lend of a CAT replacement midpipe from Ross @ Dragon Performance. I went to the local exhaust fitter and replaced the CAT. The air pump hose was tapped to the underside of the car venting to atmosphere (I never knew the hole in the air pump tube was so tiny, like a pin head!)
Once fitted I started the car and the idle was very up and down, searching, not settling. I disconnected the air pump and the revs dropped but were steady. The heat light was constantly on.
I took the car for a spin and the light stayed on at all times and the revs were low when sat at some lights.
I returned to the garage and got the car back on the ramp. I then noticed that the heat sensor connecting to the CAT was broken off, but the heat light was still on, the sensor had been broken off when the CAT was removed. While talking with the fitter we were fiddling with the car a bit. He was connecting the heat sensor that had broken off (just holding the parts together) and I was reconnecting the air pump. The idle then sounded better. When we looked at the heat light it was off? I decided to put the CAT back on because I have no PFC and also the revs were low.
Now with the CAT back on the heat light is staying off!!!? The heat sensor is not connected as it is broken. The idle is fine.

Does anyone have an idea what the hell is going on? I know I should just be happy but I want to know what the problem was.

[Donato]

Not very helpful but your car could be possessed Steve, trying selling it on ebay for a fortune!

Seriously thats very strange indeed! Sounds like the sensor could have been knackered all along...could have been shorting against itself and therefore causing problems...?