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99 ALtima P0400 / EGR Code

I have a 99 Altima with 172K on it and it has the SEL light on. I had AotoZone get the code for me and it is the EGR code in the title above.

I’ve read through the old threads on how to handle the problem, Are there any difficulties I should expect when taking the valve off and or replacing the gasket? Also, once I have it off, is there an easy way to clear the line at the same time?

Finally…HYPOTHETICALLY SPEAKING…because I would never do this and never recommend this to anyone else…since it is an older model, if one were to take off the battery cable for a few minutes before going to, say, the emissions testing station to reset the code, would the testing station be able to tell if someone was nefarious enough to do such a thing?


It should come off pretty easily. I have a factory service manual to that car in PDF form, should you need it.

As far as taking the battery off to turn the light off: it will but the emission tests readiness state is something retained by the computer. If it wasn’t ready, it waits for them all the get ready and, while the light may be off, the computer will still indicate it isn’t ready.

Thank you! I would really appreciate the service manual! I will shoot you my email address…

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