Have never passed an emissions test

TinManSC92

Registered User
going for my e-test tomorrow. my 5 speed 92 has never legally passed. nox readings were always off the charts. the only way mine gets a pass is if i run it in just after starting it up from the parking lot ( sat from night before ) and complete the test in a closed loop - approx. 2 min. - before the engine has a chance to heat up which creates nox.
i failed 4 times before that with... new cats...new 02 sensors... clean maf...new plugs...new wires...new cam sensor....blah blah blah.

this time i have new head gaskets and NEW HARMONIC BALANCER
I think i'll pass.
BTW my car doesn't have an egr. so i couldn't change that.
 
sounds like you are running a tad rich then. why not consider a tune to clean up your MAF curve and fuel table? that will net you more mpg'z and a shade more pony... plus you should be able to pass easy. :)
 
if you want to lean it out the easy way, run your tank until about a quarter tank, then add a gallon of e85. stoich for 85 is 9:1, and your computer will try to make it burn at 13:1, stoich for gasoline... thus leaning it out.

DO NOT race the engine hard or be mean to it... your engine will hate you...

just an idea... dont try this at home, nor on a closed course with professional drivers...
 
I just went through a failed emissions test on a car running perfectly fine. Like your car, the only thing it failed was NOx. Everything else was perfect. This car has always been high on NOx, but this is the first time it failed. What worked for me was pulling the octane adjust plug (by the EEC test port) and adding a bunch of gas line antifreeze (containing methanol) to a few gallons of fuel. Also, I made sure the car was warmed up (but not hot) before the test. My NOx went from 4100 to 2650.

By the way, I believe that stoichometric ratio for gas and air is 14.7:1.
 
i did the above entioned and got down to 2200 which is still a fail. i also bought the' pass in a bottle 'which didn't help much at all. i'm hoping the new balancer , new headgaskts ( cause i cleaned every part i could ) valve seals and reseating valves which were hand lapped will give me a pass. leaving for my test now. 'm thinking the new balancer alone should have helped alot.
 
and here i thought they only tested for NOx in cali.
btw mazza; do you have fairly new cats on your car? your NOx was as high as mine 2 years ago.
 
Hi,

I actually still have the stock cats on the car. 19 years and 150,000 miles old. So I am not sure if they are actually doing anything anyway. I have a set of the Magnaflow converters that I am planning to install. (I have heard from some folks that they are crap and plug instantly ... but I have also heard they are not so bad. In any case, the bends are better.)

As far as the numbers go, I don't think you can necessarily compare apples to apples. I mean, some of the testing procedures are different from state to state, and I am not even sure they measure with the same units! But I think that knowing that the limit was 3600 and my car had 4100 gives you a sense of how far off it was. That's really only 14% too high. I see that you had 2200, but I don't know what passing is for you, or what you had before you tried those "tricks." In my case, the stuff I did reduced my NOx by 35% and had no effect on my HC and CO. So 2650 was an easy pass for me, at only 75% of the limit.

As far as the testing goes, Pennsylvania has had it for a long time. But not every county has it. Most of the ones with any significant population do, though. There used to be some air quality problems out here, largely related to the concentration of industry. But a lot of that has shut down now anyway, coal plants not included. Funny story ... my college was on a hill on the eastern edge of Ohio, overlooking West Virginia. While I was there, the EPA installed an air quality monitoring station next to my dorm! People from other states, especially west coast, used to cry about the air pollution all the time. But it never bothered me, I have to say. There were a few things that worried me, though ... particularly the fact that on certain nights, the dew would trap emissions from the steel plant across the river. So when you walked through it before the sun came up, it would turn your sneakers orange. No lie. :rolleyes:
 
a couple of years ago my high reading was 3800 ppm with a pass at that time of around 900 i believe. it's now been lowered to 385 ppm for the NOx. i was way off. but, as i mentioned earlier, with all that work and new parts i knew i would be in the ball park. BTW, i never changed my cats after blowing my head gaskets either. just thought of that a while ago. then again they're only a couple years old so maybe my readings might have been even lower if i changed them again.
ORANGE HUH! i think run don't walk.:D
 
Yep, orange. But I lived. :)

Anyway, hope you can figure out something to pass. It sounds like the standards got way lower on you. Weird.
 
sounds like you are running a tad rich then. why not consider a tune to clean up your MAF curve and fuel table? that will net you more mpg'z and a shade more pony... plus you should be able to pass easy. :)

actually sounds like he is running lean. running rich will reduce NOX. the leaner you are without misfiring will always increase NOX and reduce HC and CO. one thing that will reduce NOX is pulling the octane plug. also need to verify the EGR system is actually working.
 
ya, i hope the standard don't get lower than the 385 ppm for NOx. i'll have to change my cats again after that last hg blowout. but, as i said getting into the 500's is still good and relatively low anyways.
 
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