I know this has come up time an again so when I changed out my EGR parts yesterday (EGR valve, EGR temp sensor, EGR tube) and reset the ECU I decided to monitor how long it would take prior to the MIL status to all show OK.

It took only about 30 miles. I drove it 5 miles last night after replacing the parts and 3 out of the 8 MIL indicators were OK, with 5 inconclusive.

This morning after driving to work, which is 25 miles, I checked the MIL status again and all 8 of them were OK.

General FYI for anyone who might find this useful.

 

I just finish rebuilding my engine and have driven about 100miles and i still have 5 incomplete monitors, is it supposed to take this long after a rebuild? should i be concerned?

 

It shouldn't take that long. Try driving more at highway speeds if you don't have a lot of highway speed driving.

 

after driving for about 260 miles i still have 1 inc monitor status, did some research and found this "http://www.lyberty.com/car/Maxima_A32_docs/NTB98-018c.pdf" turns out that it is quite difficult in some Nissan's to get them in to the required driving (under normal driving conditions) conditions for the test to run. I'm gonna try to follow the procedures see if i can get rid of the last one

 

For your model year, EPA allows up to 2 incomplete monitors if you are worried about getting the emission sticker. The catalytic converter monitor does take a while before it will be completed.

BUT IF YOU HAVE CATALYTIC CONVERTER PROBLEMS, THEN YOU WILL GET THE CHECK ENGINE LIGHT INSTEAD!!!

So if you need the emission sticker, do it right now rather than waiting it for the last monitor to complete unless you know 100% that you do not get P0420/P0430 codes occasionally.

- Vikas

 

You won't necessarily throw a code if you have catalytic converter problems. Well, let me define "problem." I have no engine codes and yet I still can't pass California emissions testing as I have high NOX. I already went through replacing my EGR valve and temperature sensor and did the re-test with the same results. I did have another shop replace my main cat and I still had the same high NOX values.

At this point I have an aftermarket, cattman, y-pipe in place. I will be replacing it with my original stock y-pipe and see if that gets me under the limit. Right now I am over the limit just a bit with readings about 200 PPM over the limit (limit is 424 PPM at 15MPH and 711 PPM at 25 MPH). I measured at 692 PPM at 15 MPH and 840 PPM at 25 MPH. I am thinking because the car is older now and potentially spewing more emissions the main cat cannot handle it like it could before. My previous smog (3 years ago) barely passed NOX...just barely.

It is basically the y-pipe, or my O2 sensors. The y-pipe stock replacement is the cheapest fix. If that doesn't do it, I'll have to replace my O2 sensors and bite the bullet.

 

Well, not all states do dyno test for the emission. My comment applies to the states which do not do real tail pipe test.

You will need to get OEM cat and/or OEM precats to get your numbers down. I do not think O2 sensors will fix it. A car in good tune with working cats will beat those limit by miles.

If I were in your shoes, I would be looking in to snake oils such as CRC Guaranteed2Pass or Catacleen from Amazon.

- Vikas

 

took it in today and passed smog just fine
OP, your best bet is prob to put your stock cat back, good luck.

 

Yes, which is currently happening. The f-ing shop which replaced my main cat decided to remove the flanges and weld it direct into place. As such, they have ruined the cattman y-pipe as a direct bolt on and will have to weld the OEM pre-cat into place in order to be fully installed.

Ugh...I wish people weren't such idiots when doing this stuff. They should have removed the original flanges from the OEM main cat and welded those onto the main cat they put in place. Then they wouldn't be in the current mess they have created for themselves.

Good news...I am not paying for any of this work. Bad news..I will forever be without the cattman y-pipe at this point and probably can't even sell it without the rear flange in place.

If it still doesn't pass come next week I have a hook up for a shop that can get it passed no matter what.

 

Finally passed, but barely. The NOx emissions came down about 200 points.

Looks like I'll be needing to replace the O2 sensors at some point before the next smog. Oh well...I'll worry about that when it comes.