Repairs made to intake,,how can i check intake for leaks?

Question

420 CODE after garage replaced intake to service knock sensor--garage had issue with intake removel--warped and replaced.  I see air intake possible problem. How can i check the air intake to see if it is not the problem.    All of my issuses started with repair to timing belt at garage---no check engine lite till repairs made.  Picked up vehicle from timing belt replace and all belts singing like canaries under my hood...brought back and vehicle went into a retard and died on hiway---thus the knock sensor replace and intake replacement and check engine lite

Answer 1

Hi there,

To check for an intake air leak, with the engine running, spray carb cleaner along the intake manifold. If the idle speed increases or smooths out then you have an intake leak.