Hi i am asking this for a friend and need a bit of advice on a mitsubishi carisma fitted with a gdi engine its a W reg. They was complaing about it being gutless and the revs were high at idle. Heard something about the throttle coking up on them so they cleaned it out with carb cleaner but after they did it they run it with the hose between the air sensor and throttle body off. Now the engine management light is on and it won't rev over 2000rpm. Also the breather pipe from the rocker cover to the air hose was held in with sealant and now is hanging out is this the problem or is it something they have done to the throttle body? any help appreciated. Also is there anyway of turning the light of with out taking it to garage

check there are no pipes loose on the air intake system and make sure you reconnect the hoses to the rocker cover too... the GDI has an extremely advanced mass airflow sensor (MAF) which measures barametric pressure, air flow and air temperature so that it knows EXACTLY how much air is getting to the eninge and only puts in enough fule for that air, if air is getting in through a breather pipe BEHIND the MAF the ECU just wont give the engine enough fule and it'll run lean. then it'll know it's running lean because of the lambda sensor on the exhaust, and it will asume the MAF is deffective and throw a check engine light.

I know this because when i fitted a performance air filter the engine ran extremely ritch and i actually took one of the breather pipes off to get it through the MOT, i've since taken the airfilter off and it;s fine now.


Getting back on topic, did your friends take the throttle body off to clean it? also they should take the whole intake manifold off and clean that too especialy where it joins onto the head at the top, because it has 8 very small pipes there which do get very narrow if they carbon up.