# Service Engine Soon



## jif (Apr 29, 2004)

Hey guys... I'm a proud owner of a 97 3.0SE.
My service engine soon light came on and I did a code readout myself.
I got the following:
3/4 "Knock Sensor"
7/5 "EVAP Control System"
9/3 "EVAP Canister vent control valve"

I'd like to know if these are serious problems. I know the knock sensor goes for around 150 retail. How much would the replacement parts for the EVAP valve cost? Are these parts worth replacing? 

I read somewhere that EVAP may have something to do with a loose gas tank cap.. I always fill up with 93 octane. I usually fill up my gas tank to full, and when its exactly half full, the Service Engine Soon light comes on. I'm not sure if this has any significane.

Any suggestions are appreciated. Thanks guys!


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## lawabidn (Mar 28, 2004)

Dont worry about the KNock sensor code.... its not a light setting code and you'll prob always have it (Nis Knock sensors are suuuper sensative)

You have to order/buy a Evap Canister and Evap control valve. Install them (They are behind the left rear wheel, mounted behind your mubflaps), reset your light and thats it.

-Corey


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## Estis Fatuus (Jul 17, 2003)

I recently installed a CAI and after thinking all was well, I came home and let my buddy take my car for a spin. When he returned he told me "man your car keeps dying..." I went out to take a look and the hose connecting the CAI to the Intake Manifold slipped off and the clamp went with it. I reattached the hose and put it on with zip ties, and it hasn't given me trouble since, although I think it's slipping off slowly. After starting my car again it idled normally but the "service engine soon" light was on. My clever honda buddies told me to pull a fuse of some sort or another to reset the ECU, but I was under the impression that a Nissan dealership has to reset the ECU. Any ideas... ?


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## ceasars chariot (Mar 14, 2004)

*rest ecu*

http://www.brianv.net/mods/ecu/


http://vbxmaxima.8m.com/ecu.html


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## Terran (May 7, 2004)

You should definitely worry about the knock sensor. Your car will perform like crap with a bad one. Check out http://www.skippynet.com/maxima/knocksensor.htm, and http://www.motorvate.ca/mvp.php/507 for instructions. It's a pain but definitely doable. you can get one from Jrnissan.com (use "maxima" promo code) or I got mine from an ebay seller called Yoshi-something for a little less.


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## gccch (May 16, 2004)

lawabidn said:


> Dont worry about the KNock sensor code.... its not a light setting code and you'll prob always have it (Nis Knock sensors are suuuper sensative)
> 
> You have to order/buy a Evap Canister and Evap control valve. Install them (They are behind the left rear wheel, mounted behind your mubflaps), reset your light and thats it.
> 
> -Corey


Corey,
I have the same codes appearing in my 97 Max (minus the knock sensor). You seem to get right to replacing these parts. Is it that common to see these fail? I was reading all the possibilities for these codes - including gas cap valve, loose cap, etc. Mine have been re-appearing. I just hate to replace them then find out I need a new gas cap. How sure are you?
Thanks,
Greg


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## lawabidn (Mar 28, 2004)

gccch said:


> Corey,
> I have the same codes appearing in my 97 Max (minus the knock sensor). You seem to get right to replacing these parts. Is it that common to see these fail? I was reading all the possibilities for these codes - including gas cap valve, loose cap, etc. Mine have been re-appearing. I just hate to replace them then find out I need a new gas cap. How sure are you?
> Thanks,
> Greg


If its your gas cap, I'll pay for it. I see this at least once a week at the dealership I work at. 95-98 Maxs are just getting to the age where the moisture is seizing the valves, and contaminating the evap canisers (because they are stuck open, letting moisture in)

It is extreemely rare its the gas cap, like less than 1%

and I aggree with the other person that posted about the knock sensors.... you should replace them if you see the code... but most people cant notice the difference if you drive them normal, hense the reason I dont normally reccomend them. And also because they dont set ECU lights (at a dealership, I'm used to people just wanting to take care of whatever makes the light go off) so I stand corrected on that point. I was thinking in my dealership mode 

-Corey


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