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1999 Mercedes E250 with P1401, P0401, and P0402 EGR Fault Codes - Need Diagnosis

Model: 99 E250 Fault Code: P2177 Posted: 2008-09-23 16:28

I'm experiencing persistent EGR-related fault codes on my 1999 Mercedes-Benz E250: P1401, P0401, and P0402. I've already checked the basic components and can't identify the root cause. Any insights or troubleshooting steps for these specific codes in this model? Thanks for any help.

Related fault codes

P2177

Comments (3)

Anonymous 2008-09-23 20:25

The DPFE sensor is likely faulty, and there may be restricted EGR passages. What diagnostic steps have you already taken to confirm or rule out these issues?

Anonymous 2008-09-23 22:32

I replaced the DPFE, EGR, and EVR sensors at one time—uncertain how long it's been since then. Would it be advisable to replace the DPFE sensor again given the recurring codes?

Anonymous 2008-09-25 10:34

It depends on the voltage readings from the sensors. It sounds like EGR passages might be restricted. Try opening the EGR valve at idle—does the engine stall or nearly stall? If not, you may need to remove the throttle body adapter and clean the internal passages.