[Jake Raby]

Originally Posted by Perfectlap

Would any of those trip a CEL? as in before it was too late to fix anything..

You can leave the gas cap loose and get a CEL.... You can sling a rod through the block and never see a fault code.

Of the cars we see weekly here that are failed 2/3 of them never had a fault code or CEL before they expired. The OBDII system is more centered around emissions than anything else.

Engines don't have to gain permission before they break.