MadMalx

Throttle cable will be slack, you adjust it by getting someone to put the accelerator to the floor then pulling the cable to take up the free play, then insert the clip. Once done the cable feels slack under the bonnet without any tension applied. My 1.8 exhibits the same fault as yours, again without any codes being shown up. Suggestions I've had were coil pack, dirty injector or maybe a sticky EGR valve.