1997 Saturn SW2 Q&A

1997 Saturn SW2 Question: what is wrong when you get the code p0401 and p0420 and you change and clean egr

egr and o2 sensor was change but we're still getting a code vehicle runs good what need to be done -
Answer 1
The P0401 code is for the insufficient EGR flow. It does not mean that your EGR valve needs to be replaced. It might be just the EGR ports are clogged . Its needs to be cleaned first before replacing EGR valve. P0420 code shows that your catalytic converter does not work as it supposed to . You should try a chemical first to clean converter if it wont help then converter needs to be replaced. -