Multi-code OBD2 diagnosis
Enter all the codes your scanner showed, not just the first one. We give you the overall severity, whether you can keep driving, the order in which to check them and how they relate to each other.
Summary
- Overall severity
- Medium
- Can I keep driving?
- Yes, but with caution
- Estimated cost
- $50 to $500
- Codes analyzed
- 1 of 1
The order below is the recommended one: first the codes that can cause the others. After each repair, clear the codes and check which ones come back.
Order of inspection
P0401 Exhaust Gas Recirculation Flow Insufficient Detected Medium
The P0401 code means the computer commanded the EGR system open and did not see the change it expected. Almost every time the cause is carbon buildup: the EGR valve, its passages or the cooler are clogged. It is one of the more rewarding faults to repair, because in many cases a good cleaning solves it.