1997 Saturn SW2 Q&A

1997 Saturn SW2 Question: codes p0401 and p0420 what else can i change to make this work

what are the codes i have change these parts already still getting this codes -
Answer 1
Most likely those parts shuld not to be replaced at first place as i said below. -
Answer 2
YOUR EGR SYSTEM HAS SERVERAL PARTS TO IT, WHAT PARTS HAVE YOU ALREADY CHANGED.ALSO YOUR PO420 CODE PERTAINS TO CATT EFF. BELOW THRESHOLD WHAT HAVE YOU CHANGED THERE -
Answer 3
401 is an egr code that may be a clogged passage rather than a bad egr valve. stop throwing parts at it and have it cheked correctly. 420 is a bad cat. it must be replaced. Roy -