i have a 2007 chevy trailblazer and my check engine light won't turn off.

Question

I changed my oil but didn't change the filter because it looked fairly new.  Would that make a difference?

Answer 1

No it would not. Some fleet vehicle common practice , when they change oil is not to replace the oil filter, what they some fleet environment does is drain only the motor oil , inspect that the oil filter is secured , and no leaks with the oil filter and add only oil with the same oil filter. The purpose of the CK ENG LT is to protect the catalytic convertor, and it next job is to look for open circuits, short circuit, grounds and rationality,Depending on what the code is that is set will help pin point the reason why the CK ENG LT is on