Technical high emissions

[jonnybravo88]

hi i have recently bought a fiat stilo 1.6 16v 2002 with 45 000 on the clock. after having it a few months took it for an mot. didnt need much but when it went on the emissions test it was reading 0.9 when should be 0.3 at high revs and was reading 0.7 instead of 0.5 at idle. well over. i tried using injector cleaner and a blast down the motor way nothing much happend. i had it put on the diagnostic machine and the readings for the engine and sensors were perfect. but yet well over on emissions so we narrowed down and thought it could be the cat. however a fiat genius said take the air intake pipe off to the butterfly valve and oil breather off tried it on the emissions test and went straight through. however te car has passed the test. but made me wonder why are the emessions high at 45 000 could it be burning oil? so i checked the oil and it seemed to be down after recently doing it so raised my suspicion. i did a compression test and all four cylinders were reading 75 psi and not leaking (IS 75 PSI OK?)so thought it couldnt be the rings. i looked into oil consumption and maybe it could be the valve stem seals. on the car engine cover it says the car has had the cambelt changed at 40000 this raised my suspicions again maybe it could have snapped and bent a valve slightly and they have not been re done properly. also oil consumption can be caused if there is too much clearance between the stem seals and the guides.oil consumption can cause damage to the catalytic converter higher emissions cant it? what do you guys think on this as i have never owned a 1.6 16v stilo before. are they know for this consumption? or similar problems where do you think i should be looking to solve this . can stem seals on the 1.6 16v be done without the head off? appreciate any help thanks