Where can i get my car sorted prooper or rolling roaded that wont blow my car up baring in min i live in Portsmouth south england?

If i had my car at 3.5% co leval at idle and at 3.5k in neutral would this be on the right track for 18psi then?

Il phone a mate in a bit and see if i can get him to check it over weekend.


Chears in advance Paul.