Got the head gaskets done now the idle is bouncy
 

Bounces between 500ish and 1000ish. Any ideas?

Head gaskets, valve cover gaskets, timing belt, idler pullies, spark plugs, knock sensors and vacuum lines were all replaced along with the intake and exhaust gaskets.

It also sounds like a diesel now.

Here is the idle:
https://youtu.be/e6e7F1-IlLo

Here is the diesel sound:
https://youtu.be/tWaDsEwSC4w

Re: Got the head gaskets done now the idle is bouncy
 

A couple of pieces of information:

The check valve (16195AA030) was still in the bag of leftover parts when I picked up the car. If that is left out, could it cause the idle issue?


Also, the short term fuel trim numbers are very high and erratic.

I have no qualms about re-soldering the MAF and trying that. Also, if he didn't replace the gaskets on the exhaust manifold to the pre-cats, could that cause this issue?