DaWoody

I have a P0400 code for my 5th gen 2000 Nissan Maxima. It also has a rattling sound when accelerating in gear and skips around 1700rpm. Are these last two related to the EGR error? Also in order to fully remove the EGR pipes do I have to come from under the car?

The rattling sounds low in the engine bay. It only started happening this past time when I took the throttle body off to have access to the EGR pipes

I tried cleaning the tips of the pipe with the phlange nut and the pipe that goes into the throttle body with B12 carb cleaner. Not much came out. I unscrewed the EGR temp sensor though and there was some carbon on the sensor end that I cleaned but after running the car again it still had the error code, along with a weird idling problem (the first time I took it all apart). It would sputter and want to die at low rpms so I figured I didn't tighten something right and took it all apart, and put it all together again tightly. The idle problem went away but now the knocking and 1800rpm skip is there

I took the cap of the solenoid off and the drive motor seems to screw in and out. Should it be all the way tightened before the cap is screwed on? Also how do I test the solenoid and temp sensor??

maxiiiboy

I don't have direct experience with troubleshooting the EGR system, but: The FSM provides a troubleshooting procedure on pages EC-411 to EC-419. It will take a bit of your time. Alternately, you could just replace both the valve and the solenoid but the parts will cost you a bit over $200 (see https://www.rockauto.com/en/catalog/...+solenoid,4964 ).