1996 Nissan Maxima p0325 and p0440

I have a 1996 Nissan Maxima with 113K, automatic transmission and 6 cylinders.

My "service engine soon" light came on and I can't check the codes myself so I took it to "autozon".
Two codes they reported back were
- P0325
- P0440
the car it self runs good
is just that i took it yesterday and it failed the inspection test

and i need it to pass that what can i do to make it pass!!!
the EING dosen,t make any sound
what can it be??

thanke you

You need to fix those two codes!

Moved to P0 forum.

HI ¡

The P0325 indicates you have a malfunction in the knock sensor, these problem will be fixed by changing the knock sensor (it´s located at the back of the engine in a very closed part)
The P0440 indicates a problem in the EGR valve, you should check and clean these valve. (the EGR valve is located on the top of the engine close to the intake manifold it is a round metal diaphragm shape valve) remove these valve and clean it and see if these can resolve the problem.

I noticed that some of the information provided to you is wrong in the previous responses.

The knock sensor on your 96 Maxima is located on top of the engine block, not at the back of the engine as stated in a previous response. You can see it by looking under the intake manifold from the drivers side of the engine. The knock sensor will not trigger the check engine light, but will store a code on your Maxima.

The other response is also incorrect, the PO440 code indicates a Evap system problem not an EGR problem.

A very common cause of code PO440 on the Maxima is a faulty vent control valve located on the charcoal canister under the left rear of the vehicle. You should have the evap system tested to confirm the cause of the code or if you just want to guess, you could replace the Vent Control Valve and hope for the best. Personally I would suggest you have the system tested to find the exact problem.

Good Luck!!

Not to be argumentative, but in obd II applications the MIL is supposed to illuminate whenever there is a condition that will decrease emissions. A knock sensor is supposed to trigger a code the first time the fault occurs on most (if not all conventional vehicles) and (according to what Ive experienced)will set the MIL the second occurance.
Again, Im not trying to argue, I sincerely would like to know if your post is correct. If it is, that's a valuable peice of info. Could you post back your reference please?

No harm in asking for more info..

As far as the 96 Maxima goes, as well as other Nissans, a faulty knock sensor will set a trouble code, but it will not illuminate the check engine light. I know this from experience as a Nissan repair specialist for the past 18 years and I also confirmed it by checking the information in Alldata for the PO325 where it also states that "the check engine light will not illuminate for this code".

I have worked on other vehicles that would turn on the check engine light when the knock sensor is bad, but for some reason the Nissans only store the code. I've been questioned about this on several occasions.

If the check engine light is on with two stored codes, one being the PO325 knock sensor code, the light was triggered by the other code.

I hope this info clears things up. I try to be as accurate as I can be. Thanks for asking.

Knock sensor codes always seem to be there when other codes are being checked or so it seems form posts here! again can't say I've hooked up a scanner to a Nissan without a light on and found one but it seems to be a really common code on nissans just the same! again maybe they're all bad but nobody's fixing them!

thanks chasr212r. I appreciate your response. I didn't know that. I guess EPA mandated isn't as strict as it sounds. I bet that that strategy has changed on the newer models though.