Check engine light comes on on 2005 Hyundai Elantra

was told rear oxygen sensor needs to be replace but after driving for a while check engine light comes on again.

by in Bronx, NY on November 28, 2012
1 answer 3 comments
ANSWER by on November 28, 2012
So did you have the O2 sensor replaced or just cleared the code?
COMMENT by on November 29, 2012
Yes. Sensor was replaced.
COMMENT by on November 29, 2012
And the returned code is the same as before O2 sensor replacement? What code (P----#) is present?
COMMENT by on December 27, 2012
Replaced sensor with Hyundai part. Code cleared but occasionally code PO420 comes back.
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