saxo vtr 1.6 temp sensor (HELP)

[hypersonic67]

ok ive had the car 2 months now was all good at 1st but one day i started it up and i was misfiring on idle engine management light came on :s drove it a bit it flashed at me i lost at least half the power turned the key off and on again had all power back but light still on and misfiring on idle but no misfire when driving so had i diagnostics done by my friend it came up with 3 error codes
1. p0300 - random/muliple cylinder misfire detected
2. p0115 -engine coolant temperature circuit malfunction
3. engine light on

up to now ive changed coil pack,icv,air filter,fuel filter,spark plugs,oil-filter and temp sensor started it up sounded ok for 2 mins and then started to misfire again and light on again put the diagnostics on again and same again :s

so checked what the temp are on the diagnostics and the temp sensor said -40 :S so i called the place i got the temp sensor i got one more off them and it came up same thing -40 got a volt meter and checked the voltage on the wires came up 4.97 which i believe is right it dont make sense :S also the checked the oxygen sensor data that came up

bank 1 sensor 1 0.000v
short term fuel trim 24.22% lean (-)

bank 1 sensor 2 0.000v

unplugged the lamba sensors and car run the same
so im guessing it needs two new lamba sensors which im getting tomorrow :)
hope thats fixes that problem if not i think its a new ecu :(

thanks for reading this josh

[SouthernServiceAndTuning]

have you check your fuel pump and fuel pressure

[hypersonic67]

yes there fine m8

[SouthernServiceAndTuning]

all the earth points under the bonnet, have you traced the wires back for the temp sensor

[hypersonic67]

hi i have not yet will check them on friday on my day off and ive got the lamba sensors today so will put them in friday to :) thanks m8 hope this fixes it its doing my head in lol