my car is a 94 accord ex 4dr vtech when it is cold it has good power and it hits the v-tech and flies ,but as soon as that temp guage warms up it loses power it seems like the vtech is not working i know that motor has the power cuz my brother has the same car but his is 2 dr and i eat his dust i know its the same motor f221.
any suggestions,, already cleaned v-tech sensor, has to be something with temperature. help!! its bugging me i have no power

 

my buddy suugested it is the catalytic converter cuz i have a test pipe welded in and i have no converter and the 02 sensor is not reading right

but i was thinking maybe an engine collant temperature sensor,

anyone have this problem before,i have to get this fixed im gona have to go get the computer scaned

any suggestions would be greatly appreciated thanx,