The Nissan Club banner

1 - 20 of 49 Posts

·
The name says it all
Joined
·
196 Posts
Discussion Starter #1
Hey all,


I have a 2000 Nissan Altima GXE. I recently installed a OBX 4-2-1 header. No real problems there. My service engine light came on (as expected) for my 2nd O2 sensor (because I removed the pre-cat). I know that i can have it hooked up to a computer and fix that way. But i was wondering if there was any other way to go about it.

I know that some people have talked about puttin a resistor into the wiring for the sensor. But others were looking at that as, now ur fooling the computer and it wont read the air flow correctly.

If the computer is the only way to fix it. How can fix that? Anyone who runs an exhaust place? or do i have to go to a dealership or what?



Thanks for the input and advice!


DPC
 

·
I AM LEGEND
Joined
·
10,874 Posts
A bit incorrect.The second 02 sensor does not regulate anything but make sure the cat which you now dont have is functioning properly.Thats why a clogged cat will also usally throw the dreaded P0420 code which sets off a CEL.The first 02 sensor does all the real work.That one you dont want to fool with.;)

I have had a resistor in line with my second 02 sensor since my header install.

I had one check engine light that lasted for a week and it has been months since
it went on again.Your not fooling the ECU,your just not letting the readings it(2nd 02) gathers go below a certain threshold which sets off the CEL.I actually have a Magnaflow cat inline w/ my exhuast piping,but chose to keep the sensor fooled anyway.

I know of 3 people with the resistor including the person who created the FAQ on it,Danny 7633.No one has had any issues.Check the 93-01 FAQ forum.He has the diagram and instruction shown in detail.Even if you have the shop reset the ECU,it will pop up again until you A)fool the second 02,or B)install a cat before the second 02.
 

·
Banned
Joined
·
1,805 Posts
Its wierd, I fooled the ecu, then did my swap and changed to a manual ecu, then got that CEL but it went away in 2 days and hasnt been back since.

I guess you get it once and never again, regardless I like to know when theres a real problem and not have to keep scanning for new codes randomly.
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #4
Hey again.

Ok here's an update. I followed the FAQ to a tee. I originally put a 1.5k ohm resistor in because that all i could get a hold of. but my light came back on. So the next day I put in the 1.2k I found. I had the code cleared and my light came back on after about 20 mins later of driving. will mine go away of is there somethign else i need to do??


Thanks!
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #6
Same P0420 code
 

·
I AM LEGEND
Joined
·
10,874 Posts
^OK.

Well then give the ECU some time,in the meantime you could double check your connections.
Not trying to be funny,but you do have the resistor inline with the correct wire right?

No chance you could get a pic of what you have done?
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #8
kinda a pain to pull my sensor out after doing it twice already (and kickin my own butt in the process).

Its just like Danny discribed in his FAQ quote
"o2 harness--------------------------( | | | | )------------oxygen sensor" unquote

I figure ill wait a few days n see if it goes away cuz thats the only other thing i can hope for. But I still am looking so suggestions.

Thanks!
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #9
double post lol
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #11
yes, it is on the black wire.
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #13 (Edited)
I had the code cleared after i finished putting the resistor in and no more then 25 minutes of driving afterwards. it came back on =(
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #14
Well I went to autozone because I was going to have them clear the code (like i usually do) but they told me they havent been doing that for over a year now. (*shrug*) So is there any other ways I could clear the code myself?? I know there is something about disconnecting the battery for ahalf hour. but that didnt work with my car.

Thanks again!

DPC
 

·
I AM LEGEND
Joined
·
10,874 Posts
Go to the FAQ page,there is a thread that shows the ECU reset procedure step by step.All you need is a screwdriver.

You are the ONLY one having this type of trouble after installing the resistor.
 

·
hard on equipment
Joined
·
2,104 Posts
I had the CEL stay on for a while after the resistor install, but then again I couldn't find a 1.2kOhm resistor so I'm using a 1.5 which is probably the problem. As far as I can tell for right now, the light cycles on and off about every 6 weeks, but it's off right now so maybe it won't come back on...
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #17
Of coarse I'm the only one. I'm "Gifted" with that magic touch. im gonna try that reset and see what happens

Thanks!
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #18
I dont see this flathead screw. were they on the 2000's i know some people say they're not on the 2001's. does anyone have a pic of that flathead screw?
 

·
Old Newbie
Joined
·
632 Posts
its under a white sticker if u place a flashlight over the sticker you should see a shadow where the hole is, or run ur finger nail over the sticker until you see the hole, once u find it just LIGHTLY push ur screwdriver through the hole and follow the procedure you found online, i reset my ecu after i did the intake and havent had a problem since
 

·
The name says it all
Joined
·
196 Posts
Discussion Starter #20
Well I reset my ecu today. I'll be posting back only if it does come back on
 
1 - 20 of 49 Posts
Top