MAF and harness replacement
 

So I just replaced flame MAF and wiring harness. Seems to have fixed the problem.. My Montero started right up and seemed to be running fine.
Took her for a test drive when I stopped my car and put it in park the check engine light came back on and was getting the same error code I did before I changed the parts (p0102).
I wiggled the harness a little bit to make sure it was fully connected.. Cleared the service engine code and continued for the test drive. Ran perfectly fine after
I'm just concerned the the service engine light came back on in the first place.. any thoughts?