98 Maxima GLE P0325 & P0400 fault codes

[Brajesh Kumar]

I have 1998 Nissan Maxima GLE, 6 cylinder v-type engine. I went for Emission Inspection for the first time and "Service Engine Soon" light was on.
"P0325: Knock Sensor 1 Circuit Malfunction (Bank 1 or Single Sensor)" and "P0400: Exhaust Gas Recirculation Flow Malfunction" were detected and emission inspection failed last week. The "Service Engine Soon" light came before my car had 90,000 miles, it disappeared for some time but reappeared when my car crossed 90,000 miles. It has about 91,000 miles now and it is a clean car. Please inform me how to fix P0325 and P0400 codes for emission inspection. I would highly appreciate your prompt input in this regard.

[Nahkapohjola]

Originally Posted by Brajesh Kumar

...codes for emission inspection.

When there is faulty O2 sensor as seems to be the case, it has to be replaced, 'hardest job' is to go to the shop... seek this forum for Knock Sensor, see Search at bottom.

HowTo "info", clic below. (read also page9)

[Brajesh Kumar]

Thank you for your suggestion. Before I received a reply from you, I asked the Emission inspection guy about the cost to fix the codes P0400 and P0325. He quoted upto $1200 which is a lot of amount. I have a mechanic in my apartment complex who can fix the car if he knows the location of the O2 sensor. Is there a place where I can buy the manual for my car. I am running out of time.

[Nahkapohjola]

Gettin info: First - check your options =read the web page mentioned, clic an see via top left, 'Favorite Links'.

Theres always the confuzean haynes comicrepairbook - if one isnt lost, he will be after reading... the only relevant is Nissan Factory Service Manual: Google for it, there are net shops, price around 1-200$...

The KS is about 150$, O2 about 50$. KS replacement may be costly, some do it with special tools in fraction of time what 'std procedure' requires (check out the 5c bypass possibility). Then there is the troubleshootin time: computer err codes are not reliable for number of reasosn...

Time - every one of us has problem with it here - only for our short Time in here

[nhaven]

P0400 = 0302(blink method) is most likely caused by an blocked egr tube.

http://forums.maxima.org/showthread.php?t=496494

As for the knock sensor code

http://forums.maxima.org/showthread....58751&t=479684

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

Look for the knock sensor on ebay. You can get one for less than $70 shipped.

http://cgi.ebay.com/ebaymotors/Nissa...87140659QQrdZ1

BTW, try to fix the P0400 first. Reset the code. Drive around for awhile and see if the knock sensor code comes back. The knock sensor code is notorious for being triggered by other codes.

[Brajesh Kumar]

Thank you so much for your replies. I will be doing these things this weekend. Strangely, my "service engine soon" light has disappeared though I did not do any maintenance. Now, I am not sure how to check whether P0400 and P0325 still exist after going through your recommended suggestions. I do not know how to check whether those codes (P0400 and P0325) still exist before going for Emission Inspection. I would highly appreciate your reply in this regard.

[nhaven]

How to get the codes yourself...

http://forums.maxima.org/showthread.php?t=104931

[Brajesh Kumar]

Thank you again for your prompt reply. I have seen the explanation of the codes but I am not sure whether the fault codes "P0400 and P0325" still exist as "service engine soon" light is no more there on the console. So I am not sure how to confirm whether those codes have been fixed after your recommended maintenance. Moreover, how will the emission inspection mechanic check for fixing of the above codes when the "service engine soon" light is no longer there on the console?

[nhaven]

The knock sensor code is one of the ghost codes, meaning it might still be there even though the cel is not on. My point is, there might be stored codes even when the cel is not lit. The 0302 might be gone though, which is a good thing.
Hope that answers your question.

[Nahkapohjola]

The light on dash remains as long as ECU receives error signal. When sensor inputs are ok, then light will eventually go out after clear cycle preconditions are met (or reset).

The emissions test should be pass -or- nopass, not history lesson... except on newer vehicles (here-03) when obdII code memory is read. Then after reset, one week without errorcodes is required here.

Short & low rpm drivin 'shoppin' habits cause all kinds of sludge accumulation which can be behind various problems. From engine point, its good to drive engine hot (=hour or more), 10min over 4k rpm few times a year, at least before inspection, winter... and also DIY service all connectors, see http://www.cardomain.com/memberpage/748507/14

[nhaven]

Originally Posted by Brajesh Kumar

but I am not sure whether the fault codes "P0400 and P0325" still exist as "service engine soon" light is no more there on the console.

You should get 0505 if you do the "blink method" and those codes are no longer stored.

[Brajesh Kumar]

Please inform me how to reset "P0325 & P0400 fault codes" as the "service engine soon" light is no longer there on the dash board for the last 60 miles. I am planning to go for emission inspection tomorrow. I want to make sure that the error codes have been reset in the system of my '98 Nissan Maxima GLE so that it doesn't get displayed during inspection. I would highly appreciate your prompt reply in this regard.