poor performance, poor MPG... problems :(

[97polo_16v]

hi had this problem for few months now been trying to sort it but still no luck.. ill start from te begining

are we sitting comfortably???

my car basically unperforms feels like a lack of torque and peak power, it also is a pain to start in the mornings...

right so i did my cambelt just before xmas did it in a rush and it was one tooth out

sorted it a week later but noticed power loss... this lead me to belive it was still out and took it to college were teachers with more experience could help they said the timing was fine so we put it back together and checked ignition timing which was not out... but the cap n rotor were abit passed it so i replaced them...

cleaned up the throttle body and as far as i could into the manifold...

i then borrowed the diagnostic machine to see what fault codes would come up... nothing!
we even ran live data to see what was happening but nothing outa the ordinary...

i replaced the temp sensor incase it was an intermitant fault and making it overfuel because it thinks its cold but no joy

I've recently replaced the ht leads and lambda

someone said fuel pressure regulator, its just getting to the point were im replacing anything just to try lol

WHATS WRONG WITH MY CAR!

[Mike-Mk4]

Probably not the reason, but I was also suffering from really bad MPG with the old engine.

When was stripping car to get old engine out, took exhaust manifold cover off and there was a crack in the middle, the whole way around it, lol.

Heard it is quite a common problem.

[97polo_16v]

hmmmmmmmmm

i know thers a crack between one of the ports but i just thought this was a heat expansion crack ???

i have got a stainless manifold but not put it on due to wanting to sort this problem and CAT pipe needs to be cut, in two minds weather to do it...