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Ask Juan Crespo Your Own Question
Juan Crespo
Juan Crespo, ASE Certified Technician
Category: Chevy
Satisfied Customers: 1524
Experience:  A.S.E. Master Technician, Advanced Level, Emissions - Asian, Domestic, & European
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Have an 07 2500 Hd with a Duramax giving me a P0402 code,

Customer Question

have an 07 2500 Hd with a Duramax giving me a P0402 code, has 332000 miles and never been touched, no issues with performance, just a code, does have a tapping until it warms up at low rpm.
JA: Thanks. Can you give me any more details about your issue?
Customer: Really there is nothing else, the tapping comes out as you raise the rpm's and it used to throw the code every couple months, I would clear, not coming beck very quick.
JA: OK got it. Last thing — GM Mechanics generally expect a deposit of about $32 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 1 year ago.
Category: Chevy
Expert:  Juan Crespo replied 1 year ago.

Hi there. Welcome to our site!

P0402 means the onboard computer has detected excessive flow from the EGR valve - which could also account for the tapping noise. There are tests that can be run to confirm whether this issue is caused by the valve itself or by the onboard computer - problem is you'd need a high-dollar scan tool to run those tests.

So, taking into consideration that the EGR has been there for over 300K, I'd gamble that's where the problem is. You have at least two options on what to do to fix this issue; you could replace the bad valve with a new one, or you install a delete kit with an intake elbow (click here to see both options on ebay)

Please let me know if you have any other questions.

Best Regards.

Expert:  Juan Crespo replied 1 year ago.

Hi again. Just checking to see if the information I provided helped you solve your issue. If it did, then kindly accept and rate my answer now. If it didn't, please reply.

Best Regards.

Customer: replied 1 year ago.
Waiting on parts to come in
Expert:  Juan Crespo replied 1 year ago.

OK. Please let me know how you make out.

Best Regards.