fressssssh

So went to get my car smogged the other day and it failed. /: But it's not all bad. The only major catagory it failed was NO(PPM). So my question is, has anyone had a similar situation and what did you do to pass? Here's the exact results in the NO test.

15MPH-MAX(ALLOWED):795, MY RESULT:1093
25MPH-MAX(ALLOWED):676, MY RESULT:1119

Thanks in advance for any/all help.

John_AZ

Rather than making a foolish guess, maybe these links...

https://rennlist.com/forums/924-931-...d-ca-smog.html

https://rennlist.com/forums/924-931-...emissions.html

GL
John

KuHL 951

You need a 'real' cat, not one of those generics from several years ago that last for one testing. Talk to the owner at Specialized Exhaust on Grantline/99. I went through the NOx issues on three cars in the last 18 months HC was OK, each one passed with flying colors after a new certified cat was installed. He does great work, it will cost about $200. Have clean oil, clean plugs, and make sure the cat is very hot before testing. Good Luck

fressssssh

Ok so researching some other threads I came across a reference to "E85"... what is that and will it actually work? Also thanks about the cat advice already looking into running a new one. Also how much would a new O2 sensor cost me.

John_AZ

E85
http://en.wikipedia.org/wiki/E85

O2 Sensor
http://www.frwilk.com/the944/oxygen.htm

DO NOT SOLDER the wires...
Get a Bosch or better....the cheap/generic do not have the quality materials (Platinum) to last.

GL
John

Rogue_Ant

NOx is a result of high combustion temps... retarding ignition timing will help, so will a bit of E85...
What was all your #s so we can see how close you are on the other categories?

kev951

you can try putting some high octane unleaded 104 race gas and that should bring the nox down to just barely passing ( could be a result of carbon in you combustion chamber, or using bad gas, or just an old or cheap cat, can you post all of your resultS? co2 o2 nox hc and co at both speeds, I can get an overall lambda reading with the results and point you in the right direction. If your 02 sensor is faulty, you sometimes have multiple fail results and or your CO readings would be around 0 or extemely lean ( which will pass , but is an indicator of a lean mixture.)

nox is a result of too much air (running lean), detonation, pinging, incorrect timing, wrong octane gas, bad cat, bad egr (not for us), bad o2 sensor if stuck rich ( computer thinks there is too much fuel, so it will lean out the mixture) , and sometimes a bad VAF or MAF. Of course a bad cat, or to much carbon in the cc chamber is also very likley on an older car. A vacuume leak will draw in more air, and if your ECM reads the difference of the added air , it will add fuel to compensate and you will run a richer mixture, and have much less nox.
lean conditions = higher nox and o2
rich conditions = higher hc and co and less 02

an easy way to to check if your cat is still functioning via test results is : for both speeds, add up co2 and 02 % ( if the totals are 14.5-15.9%, your cat is oxidizing and reducing and your problem is not cat related) so at 15 mph if you got a co2 reading of 13.8% and an 02 reading of 1% or slightly higher, your cat is working) Basically to sum it up, if your co2 and o2 add up to 15% ish, you have good overall engine efficiency and a good cat. I can get way more thourough, but these are just some basic guidelines,

I am a licensed Enhanced area certified smog tech here in the SF bay area.

fressssssh

15MPH-2840RPM-14.34(CO2%)-0.23(O2%)
HC(PPM):MAX:95-MY RESULT:75
CO%:MAX:0.58-MY RESULT:0.23
NO(PPM):MAX:795-MY RESULT:1093

25MPH-2832-14.40(CO2%)-0.19(O2%)
HC(PPM):MAX:77-MY RESULT:63
CO%:MAX:0.44-MY RESULT:0.18
NO(PPM):MAX:676-MY RESULT:1119

Rogue_Ant

What FQS position did you test at?

fressssssh

Idk what FQS is. Lol

Rogue_Ant

See link:

http://members.rennlist.com/951_racerx/FQS-adjust.html

John_AZ

Great link!

The Warning at the bottom was new to me.

Thanks

John

fressssssh

So then I'm guessing mine is set to stock, but just to make sure I'll check tomorrow. But if its stock what should I set it to?

fressssssh

FYI: I only put in 91 gas so does that affect anything?

Rogue_Ant

If it is set to stock (position 0), then try either position 4, or 5. Both 4 & t will lower NOx, but position 5 will also increase HC... You have a little bit of wiggle room with HC.