You didn't mention cleaning the connector itself. I think that has been the fix more than once, especially when water gets into the contacts. We kinda assume you've done some ohmmeter checks already. I strongly doubt the code will appear due to some degradation in thermal conductivity of the coolant in the head.

--
Art Benstein near Baltimore

Those of us who spent our allowance at the five and dime think we are getting a bargain at the dollar store.