Hey I have a mazda 323 that have been driving perfectly. But one morning while driving to work my car feels slow and won't take full throttle I see that the TCS OFF button is also showing and after driving with this problem I have seen that as soon as the car does not display TCS which is sometimes don't because of a lose circuit or something. It drives perfectly. It also can't keep a steady idle number, and when I push the clutch down it sometimes shuts off. Leaving me with a very hard wheel to turn if I am in a roundabout or similar.
I have been at a mazda car mechanic but they said it was a bad wire, but they couldn't see where so they wanted to check the car again for around 140$ an hour which I am not about to spend on an old car like this.
But to summerize what I have done so far.

I have replaced the air mass sensor
Also the sparks (also wiring)
Also the camshaft sensor
But with no results.
I have tried to see if anything was lose multiple times but can't seem to find anything.

Anything at this point would be appreciated.
Also something to note is that the car after displaying TCS OFF it has also changed how long I drive on a liter. So before I could drive around 13 km/l but now it's halfed at around 6-7.