Hello. I was driving home from work the other day and saw my engine light pop on. When I got home, I checked the car with my little diagnostic scanner. The scanner read "knock sensor" code and "exhaust gas circulation malfunction". Has anyone else had this combo before show up? One other time I had the knock sensor come up but never came back after clearing the codes. Yesterday, I went ahead and reset the computer and cleared the codes. I figure if they both come back on, then I'll deal with it. But I know ECU's do weird stuff sometimes and it might have come on for no reason. The only thing I've done to the car recently is put a Y-pipe on and that was about 500-600 miles ago. I always use 93 grade gas too. Let me know any info if you have any. Thanks in advance.

 

The KS code is the main concern. If you get it again I'd replace that first. When that goes it usually leads to other odd codes. How many miles you have?

 

I currently have 78K on mine. At what mileage did yours go out? Or has it? Also, how difficult is the task of changing it?

 

Well, my engine light once again came on yesterday. It has been around approx. a month and a half and 1000-1500 miles since I reset it last. P325 and P400 popped up again. Knock sensor and exhaust gas recirculation malfunction.

Think it's time to condemn the knock sensor or could it be a bad tank of gas? I use 93 octane all the time. What approx. price would I expect to spend on a knock sensor in parts? I'd like to change it myself, but would like to hear from others if it's something I could tackle by myself. How long did it take some of you to change it? Thanks for your help.

 

Fix the EGR 1st, and the KS code may go away too. The replacement KS costs $160-$200.

DW

 

I did a search and read up a little on this. So I should take it in for an EGR cleaning? How much ballpark does the dealer charge for such a task?

I would do it myself, but this is my everyday driver and I'm a little fearful of not hooking a vacuum hose back up to where it's supposed to go or vice versa. How imperative is it that this is done soon? Is it something to get done ASAP or is it not terribly detrimental? Thanks

 

I couldn't tell you about the EGR problem, I've never experienced it. I just know its bound to be less expensive than the KS, and the KS may be a false alarm due to the EGR

DW

 

Has anyone had an EGR cleaning at Nissan? If so how much?

 

bump

 

I'm having this exact problem right now P0325 and P0400, which is Knock Sensor and EGR, so I searched and found this thread (6 years late).

Is there a set solution to this problem now?
If anyone could help I would appreciate it.

 

Replace the KS and see if the other code pops up. Sometimes you can fix one code and make the others go away.

A common one is a KS (P0325) and bank 1 and 2 sensors running rich. Found out my KS was split in half! Replaced that and my car pulled strong immediately.

 

Alright thanks, I'll try that this week and if it keeps up then I'll go from there.

 

Hope you got small hands or maybe use those ratcheting close end wrench, I replaced my KS and ended up with a million scratches on my hand and knuckles..

Check out this site for how to replace KS:

http://motorvate.ca/mvp.php/507

 

Yea I know. I replaced it and it wasn't fun! What I found helpful was that if you remove your intake piping which connects to the throttle body and after it will be ALOT easier. And if your leaning towards the engine from the drivers side fender you can use your LEFT hand not right and unbolt and bolt the KS like that, but make sure your palm is facing towards you! This will also make it easier to do. If you do what I say this removal and installation will be less complicated. Another tip about installing the knock sensor is to put some sort of tape on the bolt so when you position it, it wont fall out to a place you can reach. I taped half the sensor and bolt together.

If anyone has questions about replacing a knock sensor send me a pm. I will be willing to help if needed. Oh and make sure you have a foot extension at the least. Will be better.

 

Hello -- I had this same situation, the 325 and 400 codes, which tripped a few months ago. The yellow light goes on in the dashboard, and my car is at 111K.

My solution
1) Changed the knock sensor with one from ebay -- it took an hour, but I could do it much quicker if I had to again
2) Cleaned the EGR tube. Look for my comprehensive pictures and directions on how to clean out the EGR tube.

Both codes are gone after 500 miles driving