Q: Check Engine Light Stays on since purchase of 02 kia sedona with 89,000 mileage. on 2002 Kia Sedona

Rookie cbe0621eac06868b3efe0d8d1d3611e23c60d3114864ea2ec19a68cfbd3eebab
Now engine is sputtering and recently began knocking lioke metal clinking in engine when started and now that knocking began ----lasting longr after warming up....mechanic I called said check engine oil level...when I did black tarry gunk was at tip of stick...looked like no oil above that....But no oil light ever came on and seller said oil had just been cchanged!
(1) Answer
FIRST- oil light is for PRESSURE NOT VOLUME. A motor can have one quart of oil in it and still have great oil pressure at idle. Second, seller said it was just changed , did you or somebody with you verify this visually? Did you top-off oil after discovering it was low , to see if this helped the knocking noise? Last- how many miles have you driven it under these conditions? Check engine light is probably on due to a valve control problem related to the low/sludged oil.