i took the auto computer out because the car was always in the wrong gear (too high)

i put a new one on and it was still the same..

when i was putting the old one back on i took the plugs on and off two or three times and when i took the car for a drive it went perfectly

so i guess the plug was dirty or the connecters corroded

all's well that ends welllol

interesting that the metal has corroed being INside, hmm maybe check you dont have any leaks around there??