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David, Hot Rod Shop Owner
Category: Car
Satisfied Customers: 73
Experience:  10 years in automotive industry from oil changes to complete vehicle design and fabrication.
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2002 Oldsmobile Alero 3.4L P0401 fault code. Had excessive

Resolved Question:

2002 Oldsmobile Alero 3.4L P0401 fault code. Had excessive carbon in egr valve & valve stuck open at 50%. Replaced valve & cleaned all carbon deposites in pipe & intake. Had bad map sensor, replaced & fuel pressure regulator seem was leaking, replaced regulator. Fault code came back on. What else could be at fault?
Submitted: 8 years ago.
Category: Car
Expert:  David replied 8 years ago.
The code P0401 shows low egr flow.There is a passage in the upper intake manifold that is most likely plugged up with carbon keeping the exhaust gasses from going back into the motor. The passage is between the egr valve and intake. You will need to do is remove the egr valve and clean this passage with a pipe cleaner and carb cleaner.

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