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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15181
Experience:  GM Grand Master Technician 2007. 14 years experience.
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I changed egr value and now it's giving me po401 code, Yes

Customer Question

I changed egr value and now it's giving me po401 code
JA: Have you scanned the code? Have you tried to reset it?
Customer: Yes it clear po400 code then the light came back on. I checked again he gave me the po401
JA: What is the model/year of your Chevy?
Customer: Impala 2004 3400 engine
JA: Are you hoping to fix this yourself? What have you tried so far?
Customer: Auto store to put injector cleaner couple of tanks of gas that didn't work yes iam fixing myself
JA: Anything else you think the mechanic should know?
Customer: No
JA: OK. Got it. I'm sending you to a secure page on JustAnswer so you can place the $5 fully-refundable deposit now. While you're filling out that form, I'll tell the Chevy Mechanic about your situation and then connect you two.
Submitted: 5 months ago.
Category: Chevy
Expert:  Jared D replied 5 months ago.

The p0400 and p0401 are both a result of clogged EGR passages on this vehicle.

It most likely needs to have the EGR passages cleaned out. Do you plan to repair this yourself?