The intake manifold gaskits have to be tigtened down in a certain way, starting at the middle and swirling outward to ensure no distortion and excessive pressure. On the shoc the manifold is plastic. This is a job I did on mine not so long ago as part of the dreaded 00m12 timing chain tensioner job. The rest is easy to do at home so please get the parts, search the threads here and do it in a logical and planned way, start with the plugs, then fire up the car and you know thats working go on to the manifold gaskits, then the rest one by one........checking for running after each job. You cant go wrong that way and will have the satisfaction of knowing the Fraud have not turned you over for cash for the gibbons to have a lame attempt at your car!