I get a recurrent 0400 DTC.

I'll clear the code and I get no DTC for about 2 to maybe 3 weeks then it will recur. I've gone through this little procedure about 4 times now with 2 to 3 weeks of code-free-ness in between.

I would think that if the the typical EGR tube clog was present then every time the EGR is triggered, the clog would prevent flow and the code would be logged. But that doesn't seem to be the case here as evidenced by the recurrent but intermittent code.

Would you guys suggest that perhaps this is a failing valve or sensor as opposed to a clogged tube?

I doubt its a clogged tube, cause I cleaned mine a month ago, and still get the code. Its probably your evap vent (by your rear left tire facing the tire on the evap box, or your evap box is clogged). Well I just noticed its 0400, not 0440. I say clean the tube, and the sensor.

Don't know if this will do it for you, and it shocked me.

I used to get the 0302 (P0400) code intermittently as well. For months, it would come on for a while, go off, I might reset and it would come back. Even cleaned out the tube when I was in there with all the intake off for a KS replacement. Still didn't help.

What finally fixed it? A new air filter.....

Try at the very least cleaning yours out, but I'd just replace it. We're talking $15. Mine was old/dirty enough that it impeded flow to the degree the EGR high/low pass sensor got tripped apparently. I had regularly cleaned it out and it wasn't too old, but apparently had just gotten clogged enough to cause a problem in the flow.

After replacing the air filter, never came back again. Nothing else was done.

-DPF

Clean the tube, it's a known issue.

yah, clean the tube. Very big known issue on our maximas in this gen because Nissan did not make a great discision when they made the EGR tube as it has a bend in it. The carbon builds up over time and bam, clogged.

I had this code almost 3 yrs ago and has not returned. I changed a part called EGR solenoid valve. Check these threads for more details regarding this issue.

http://forums.maxima.org/oldthread.php?t=350528
http://forums.maxima.org/oldthread.php?t=516825&page=2
http://forums.maxima.org/showthread.php?t=372440

clean the tube braaahhh even if thats not its still benefitial to the car and ull gain a mile or 2 per gallon for that.

Changing the EGR solenoid valve cured my EGR problems as well. I was getting the DTC 32 more and more frequently, and having the tube cleaned didn't help.

Sol. valve was Nissan part #14956-31U1A (for my 95 SE) - $89.26 + tax from the dealer.

I too get the same code. I did buy the parts (the gaskets) a few months ago. I need to locate them parts and just do this job but I just passed emissions last month so my incentive to get this done is gone. I have been getting 325 or so miles to the tank for years even before that CEL so I know my MPG is fine.

If you're referring to the solenoid valve, no gaskets are needed to replace that. This valve is pretty easy to replace - hardest parts were getting the 3 rubber hoses off (mainly cause they had never been off in 14 years) and, of course, getting to the 10 mm nut holding the valve on.

Is this the same part # for the Fed spec 1997? I'm dealing with the 0801 code and its blaming the Vacuum Cut Valve Bypass Valve which I believe is the same thing you are referring to. Does anyone know where I can get the part number if that isn't it, other than driving to a Nissan dealership. I would rather get it from Courtesy Nissan.

Hmmm, I gained mileage by just disconnecting the EGR altogether. Car runs a hell of a lot better too.

I just don't have the patients now a days to pull and clean the tube.

^ ha, yah same here... =/

Sounds like you have a completely different problem than I had. I couldn't find any `vacuum cut valve bypass valve' nor any code 0801 in the service manual for my 95 SE. Obviously something was added between 95 and 97.

I definitely kept getting a 32 mil code (likely a P0400 consult code, though I never bothered to even check that) every time my MIL light came on. The DTC 32 (EGR) trouble diagnosis section of the FSM pointed to either the EGR valve itself, the EGRC-BPT valve, the EGR & canister control solenoid valve, or the EGR temp sensor. After getting the tube cleaned and still repeatedly getting the 32 code, I took a chance and replaced the solenoid valve. Plus, of the 3 EGR valves, that one was the easiest to replace and (as I mentioned previously) was less than $100 new. So I figured replacing that valve was worth a shot, and I lucked out.

As for a part #, any Nissan dealer should be able to give you that (along with the price) over the phone from an EXACT description of the part - preferrably obtained from the FSM. With an approximate description or name of the part you think you need, who knows what you'll get.

Are you a doctor?

(sorry, I couldn't resist)

Yeah, you got me.....

Can you please point me towards instructions on how to disconnect the EGR system?