FWIW, I try to keep track of all modifications or changes and maintenance I do to the cars. Invariably problems like this show up AFTER I change something or do something (like the several years I had problems with rising rate fuel pressure regulators from a Saab aftermarket supplier--they fixed the RRFPR both times and I learned to test for fuel pressure when driveability went to heck)....and I can then go back to the way it was before I hacked it up.

Now if I could only figure out the durability failures as easily.