Well I took my car to get smogged and it failed. I live in cali and have a 98 i30 by the way. On the printout that I have the only area where it failed was the "NO (PPM)" @ 15 mph. The max allowed is 430 and the machine measured 757. What's weird is that the max allowed at 25 mph is 717 and I got a 448. My mods are:

Y-Pipe (I drove around for about 45 minutes before and the guy tested the car 3 times for me)
Technosquare ECU (replaced with stock ECU for the past week & for the test)
JWT Intake

The car has 77000 miles on it and I just changed the oil less than a week ago, but I have NOT done any other service to the car. I have a new set of spark plugs & a new fuel filter that I need to install soon. Will installing these lower my NO score? The guy at the smog shop told me that it might be the O2 sensors or the EGR system. Anyone else had a bad NO score and then got it fixed. Any help is appreciated. Thanks.

 

new air filter could only help..

 

I'd also like to know how to lower the NO (PPM) value. When I smogged mine, the measured value was 424, with the max at 437.... So I barely passed.

I had a really dirty filter in there at the time though. Other than that, the car was stock.

 

I read a few threads and it looks like I may need to clean the EGR valve. At least that is what worked for some of the 3rd gen guys. Where is the EGR valve for our cars? I will also clean my air filter I actually bought the cleaner kit on my way to get my car smogged.

found this link but I can't really see where the EGR valve ishttp://autoclinic.net/article/imports/nissan_p0400.htm

 

i have the exact same problem. i went in to get smogged and i failed cus my no ppm level was 685. could you please let me know what you do to fix this problem?

 

I was reading another forum (bimmerforums) and the folks there recommend a new air filter, fresh oil and oil filter, drive the car around at least 20~30 mins (keep the car on and rev it while waiting in line to get smogged), use "name brand" gasoline like Chevron, add a bottle of fuel injector cleaner, change spark plugs, check/change o2 sensors.

This is the post it came from:

http://forums.bimmerforums.com/forum...light=smog+PPM

 

Have you done an engine flush lately? Auto-Rx engine treatment will make your car better.

I've also seen in auto stores that they have some fluids to help pass the emissions test. Try it.

Change the fuel filter, and get your fuel injectors cleaned professionally.

I would not go change your sensors if they are not broken. Waste of money. Check the ECU to see if you have any codes. The stickys will show you how to do it.

 

Wow, after reading this, it makes me damn glad that there arent smog checks where I live. Sounds like a real pain.

 

yep, no smog checks in alabama...here people ride around without mufflers and without cats too.......Glad to see the west coast is picking up the slack..lol

 

You can also pull one of your main vacuum line and let the fuel injectors sniff some fuel system cleaner. That will drop you co and no levels maybe enough to help you. Walmart sells a brand that is safe for the fuel injectors...its been a while since I did it and I cant recall the name...its like what they do at those speedy lube places by dripping in a cleaning solution slowly over the period of 15 minutes. We had a guy fail his emissions miserably on his 77 deville and ran a FIC (fuel injection cleaner) and passed no issues. With your no mods and no knowing the cars history I cant guarantee it but its good info FYI.

 

great, i'm going to run into the SF, CA smog ***** myself soon. cai, ts ecu, ypipe. sounds like i'm going to need some luck to get through this one.

 

Thanks for everyone's suggestions.

My car didn't fail that badly. The only catagory I failed in was the NO @ 15mph. Everything else was good. I think you should be ok if you do a tune up first. I still haven't done my 60K service or anything to the car for that matter since I got it at 38K (I'm now at 77K).