Sticking the PCV valve would cause a ‘vacuum leak’ which allows too much air into the intake plenum (bypassing the MAF sensor) This can of course cause lean and possibly ‘knock’
It seems to me that you have solved the PCV problems.
———————
I can’t say this more briefly — STOP swapping parts blindly !!!!
Shooting a ball at a problem is NOT a good way to solve problems. It often results in creating MORE problems on top of what you currently have.
Aftermarket parts (from the autoparts store) are often bad right away or never work properly. They are known to make things worse.
DON’T bother replacing the “knock sensor” is NOT the problem.
Also do not replace the plenum intake gasket without TESTING if it leaks.
The vacuum leak test is irrelevant… While the engine is at idle (highest vacuum in the plenum) spray something like engine start spray around the gasket. (gentle explosions… DO NOT cause fire.)
- If the engine speed changes – suspect a vacuum leak
- If the engine speed does NOT change. There is no leak in that area.
In fact, you can test for vacuum leaks ANYWHERE using this technique. (not only gaskets)
——————–
Also consider cleaning the MAF sensor.
———-
I guess what I’m saying is, it’s FARRR better to test, test, and TEST some more to determine what’s causing a problem….then fix it. (People who throw parts at a problem are just guessing and often end up with more problems if they use auto parts store components)
Never forget that a “new” part does not mean it is a “good” part. In fact, a tried-n-tested used part is far superior to a “new”, unknown part.
