hi could any body sugest what is wrong i have a 2002 2.0 non turbo and it is jerking and flat spot up to 2500 revs after that its fine could anybody help.

 

blocked cat , bad fuel pump or relay , maf sensor , throttle position sensor , blocked filter box or air feed pipe , water in the air intake ( puddles etc ) blocked fuel filter lol
nobody gets replies when a sport is mentioned lol could be anyone of the above mate , take it to get the fault codes read and u will probably find out instantly what it is , do u know any 1 with a select monitor as that is what you need to read the codes ? if u dont then garage or subaru themselves

 

thanx for the reply i no every body rips the sport lol i hve got my own code reader nothing is showing there is no cats on the car filters are fine all new no water i thought of the maf sensor but wanted to try other options before i buy a maf as they are expensive.

 

i no probably no body wants to help me because it isnt a turbo but if it helps i used to have a classic sti but couldnt afford to run it as i have a heavy foot and just had a baby so had to go for the looks and not power.

 

try re-gapping the plugs ? this helps on the tubbys so shouldnt see why it wouldnt do the same on the sport as they are still boxers lol

 

Also check your lambda sensor voltage is cycling between 0 and 1 Volt (approx) - If it's failed then will cause the car to run really rich in closed loop, giving the symptoms you describe