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Discussion Starter #1
Hi,
I recently failed emissions and am pretty sure there is nothing wrong with the car but wanted to get verification here. The only problem I can think of is that the car was sitting around for at least a month (possibly two) and it had definitely been 2 months since I had put any gas in the car. Can approximately 2 month old gas and sitting around for a month cause failure of emissions test? If I drive the car all this week, using only highest test gas, and possibly using fuel additives that help pass emissions tests, will I more likely pass emissions if I take the car in again next Saturday? Thanks for any comments...

Kurt
Blue '83 Ptype manual with failed emissions :(
Brown '84 Ltype automatic
 

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What exactly did it fail for? High HC, NOx, CO .... ? I'd highly doubt just sitting around alone would cause it to fail.
 

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Discussion Starter #3
Hi,
I am terribly sorry for not answering sooner. Work life is getting quite hectic. Anyway, the numbers....

HC ppm @ 15 mph: Limit 140, reading 57 PASS
CO% @ 15 mph: Limit .79, reading .13 PASS
NO [email protected]: Limit 1097, reading 1591 FAIL
RPM 2849 VALID
Dilution 14.7 VALID

HC ppm @ 25 mph: Limit 135, reading 136 FAIL
CO% @ 25 mph: Limit 0.83, reading .36 PASS
NO ppm @ 25mph: Limit 999, reading 2405 FAIL
RPM 2787 VALID
Dilution 14.9 VALID

So basically I failed NO ppm at 15 mph and both HC ppm and NO ppm at 25 mph. My NO ppm seems to be WAY over the limit. GreyFalcon: It actually says here it PASSED the gas cap pressure test, that's with the old original cap. Inspection of EGR system, PCV system, Catalytic converter, and Fuel evaporative system all show as PASS.

Again, if anyone has any thoughts on this matter I'd appreciate hearing them. Thank you in advance!

Kurt
 

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I would suggest removing the EGR valve and do a cleaning and inspection. They tend to get clogged up after 20yrs of use, and it will send the NOx readings sky high. Also check the function of the vacuum modularator and vacuum plumbing as well. I'm not to sure how thorough the smog inspection is where you are at, but their "pass" might have been more of a visual than a functional inspection. My last suspect would be the converter. Generally all the #s will be high when the converters dying, they usually last a long time though. Your HCs are a little high as well. If your car is burning oil, running rich, or miss firing will cause this.
 

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Kurt;

High NO numbers can often indicate a non-working or plugged up EGR system.
I realize it says that your EGR passed, but if your inspections are like the ones they do here, all that means is that the guy/girl looked to see that the EGR system is still installed on your car and has vac lines running to it. It doesn't mean that he/she actually checked to make sure it was working properly.

Here's a link that you might find helpful as well.

http://www.smogsite.com
Tons of great info on all the systems that reduce/control emissions.
 

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EGR system probably to blame. Easy way to test is with a vacuum pump.

1. If you can draw a vacuum on the EGR actuator with the engine running at idle, the engine should stumble, indicating that the passage is clear and the valve is working.

2. Now, the same vacuum line that goes to the EGR actuator, hook the vacuum gauge to it with enough hose to run around the windshield into the car. Drive around the block, motor should be warmed up. As soon as you step on the gas to accelerate, vacuum should go from zero to a few in hg. If you accelerate hard, the vacuum should go to zero again. If so, the vacuum modulator next to the EGR valve is OK along with the temp switch. If not, there are more detailed testing procedures in the TSRM to see if its the switch or the modulator. If 1 and 2 are OK then the EGR system is OK and perhaps the cat is fouled.

3. If test 1 indicates a blockage, remove the EGR actuator and attach the vacuum pump. You should be able to blow through the valve when you apply vacuum and it should be sealed when the vacuum is released. If the valve is OK, then

4. There's a 18mm plug on the top of the intake plenum dead center. Poke a nail or such through that plug and with a big screw, pry it out. You'll see that the EGR passage is completely plugged at this point. I ran a small hose from my shop vac into the intake plenum through the throttle body to suck up the crud as I chiseled it out of the passageway (otherwise the chunks fall inside the motor). Also, there's an allen head stud at the rear of the plenum that you can take out and run some wire through to clean out the entire passageway. If its still blocked after this, then its probably stopped up at the EGR cooler on the back of the motor. You can remove the steel tube and I found that you can ream out the cooler pretty well using a long shotgun cleaning rod with a 20ga brass bristle brush. Oh and be sure to get a replacement plug before you start. You can tap the new plug back in using an appropriate sized socket and extension.

We Texas Supra owners have had to learn this year since they started doing california style emissions. They never tested for nox before 02 so of course we were all blissfully unaware our EGRs were plugged up for the last 50 or 100K miles.

Phil D.
 

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Kurt, may car had sat for a number of months before its recent smog check. I ran 2 tanks of new gas then used CRC Emissions additive thru for almost 14 gals then tested.

Sup readings

IDLE: Max allowable
HC ppm 25 120
CO % 0.01 1.00

2500 rpm:
HC ppm 16 150
CO % 0.03 1.20
 

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I also replied to your post about the 93 octane fuel in a 91 rated car, the answer below is similar to that which I posted there.

When taking the car to be tested, drive the car for an extended period of time before arriving to the testing station. Drive the car for atleast 30 minutes, if not more, at speed (not idleing). Allow the engine to reach full operating temperature, only then will the engine, egr and catalytic convertor do their respective jobs properly. A cool engine and cat will allow all sorts of hydrocarbons and NO mixtures to pass thru the exhaust. A hot engine and cat will burn off the majority of these byproducts before they can make their way to the tailpipe. Also, another important tip!! DO NOT allow your car to sit and idle for an extended period while waiting in line at the testing station. This will cause build-up of gasses. If needed build the RPM's every so often to blowout any residual gas and/or oil.

I had a similar firsthand experience a few years ago in Ohio. It was time to have the 85 Celica tested (in OH it's only neccessary to test every 2 years) and since there was a station close to home, about 4 miles, I decided to go there. Needless to say the car failed miserably even though the temp gauge showed that the coolant was at normal temp. A few days later I went to another testing station close to work. Only this time I drove the car for 20 miles or so, both on the road and on the hiway. She passed with flying colors! Comparing the numbers (I can't remember what they were) was incredible, a HUGE difference.

Weekend with the babysitter.
Scott
 

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Discussion Starter #9
Hi,
No there is no waiting in line at the emissions station. It's just a gas station in a small town that happens to do emissions inspections... no repairs! Anyway, like most other garages, you just drop the car off and leave. They call you when your car is ready. Therefore, the risk of a cold car is still there if they wait a few hours before inspecting. So I've decided to do all I can in addition to warming the car up as much as possible. I will have replaced the EGR valve, the plugs (with platinum ones), the wires, the distributor cap, button and gasket. This is all I can afford to do right now. I hope its enough. The cat is aftermarket and is a good 2 years old so there is that possibility as well (probably close to 40000 miles on the cat). Thanks for responses, I will post results of next test sometime saturday april 12.
 

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As Arch had mentioned, use that fuel additive. I've seen it but never used it. The bottle states, "guaranteed to pass". A friend of mine swears by it.

After years of heavy drinking, bright lights and late nights, I still don't need glasses. I drink right from the bottle.
Scott
 

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Discussion Starter #11
Retest results

Hi,
This time (after replacing only the distributor cap, button, Oring, plugs and wires) I passed everything EXCEPT for NO ppm. The results from last time AND this time are:

LAST TIME:
HC ppm @ 15 mph: Limit 140, reading 57 PASS
CO% @ 15 mph: Limit .79, reading .13 PASS
NO [email protected]: Limit 1097, reading 1591 FAIL
RPM 2849 VALID
Dilution 14.7 VALID

HC ppm @ 25 mph: Limit 135, reading 136 FAIL
CO% @ 25 mph: Limit 0.83, reading .36 PASS
NO ppm @ 25mph: Limit 999, reading 2405 FAIL
RPM 2787 VALID
Dilution 14.9 VALID

--------------------------------------------------------

THIS TIME:
HC ppm @ 15 mph: Limit 140, reading 77 PASS
CO% @ 15 mph: Limit .79, reading .07 PASS
NO [email protected]: Limit 1097, reading 2383 FAIL
RPM 1732 VALID
Dilution 14.6 VALID

HC ppm @ 25 mph: Limit 135, reading 89 PASS
CO% @ 25 mph: Limit 0.83, reading .15 PASS
NO ppm @ 25mph: Limit 999, reading 2060 FAIL
RPM 1924 VALID
Dilution 14.9 VALID



SUMMARY:
As you can see, my HC ppm @ 15mph went UP 20 units??! My HC ppm @ 25 mph went down to 89 and therefore passed this time.
I cut in half my CO percentage (from .13 to .07 @ 15mph and .36 to .15 @ 25 mph).
My NO actually got a lot worse @ 15 mph... from 1591 last time to 2383 ppm this time.
And finally, my NO got better at 25 mph (but not good enough) from 2405 last time to 2060 this time which is still way off.

Last time AND this time I ran the car hot (using 1 or 2 gears lower than what I should have) for at least 30 minutes with a fuel additive. This was in order to get the cat good and hot. Today I will get to pick up my EGR valve and will install it and TRY AGAIN. I HOPE HOPE HOPE its not the 2 year old (aftermarket) catalytic converter. It cost me almost 500 bucks from MIDAS... I don't want to give up on it yet!!

QUESTION:
Does the fact that NO is the ONLY thing that failed give a greater clue as to what the actual problem is? Thanks again for any input!

Kurt
 

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Discussion Starter #12
Hi,
Just to wrap things up, I replaced the EGR valve which only reduced my NO readings from approx 2300 to about 1700. Significant but not nearly enough. Then (finally) I got the catalytic converter replaced (same as on a 92 Corolla according to The Tire Shop's mechanic), and the readings are MUCH much lower, like aroun 300 or less. ( I don't remember the number right now). The culprit the whole time was the cat but I was in denial for awhile. At least now I have a new cat, EGR, and tuneup. I should be green for quite awhile :)
Thanks for all input on this topic :)

Kurt
 

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:mad: :mad: :mad: :mad:
Well i guess ill add to this topic
I went to go and smog my white car today. And IT FAILED :x ARRGGGG
It Failed HC (PPM)
-----------Max GP Meas
15MPH- 130 306 213
25MPH- 105 256 196

It also Failed in CO(%)
------------Max GP Meas
15MPH- .08 2.31 .86
25MPH- .61 2.11 .86

and it also failed on NO(PPM)
-----------Max GP Meas
15MPH- 1115 2123 3068
25MPH- 945 1923 3355

so it gave me Gross Polluter for both the 15MPH and 25MPH
What could have casued these numbers to be so high?
I was planning on getting a new EGR vavle and new cat. What else can i do to make sure it should pass?
<---who hates his SMOG NAZI STATE
 

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FALIED WITH MY BLACK 85

The N O was to high, on my black 85 supra with 189000 miles,cleaned EGR SYSTEM,stilled failed but improved,dumped in CRC EMISSIONS CRAP,and two tanks of fresh gas,no improvement stilled failed,now I placed on a cat from my 82 with low miles and is 17 inches long compared to the 85 that is 12 inches long.Will test next week,doesn't pass it goes in the FOR SALE SECTION.
The 82 TURBO SUPRA passes the tailpipe test with no cat or egr.
 

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:mad: Im kicking myself in the ass ARRGGG
I know know why it didnt pass somog. GUTTED CAT!!!!
I was putting on my headers yesterday, and I thought to my self I never check the cat when i had the engine out. And, Low and behold the cat was gutted out. :mad:

ohh well, I just got my catco cat to put in soon.

(too busy right now to go to a local muffler shop to get it installed)
 

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ARRGGG I cant seem to make my car pass smog HERE IN CALI :mad: I cleaned out every possible thing and put in a new cat, and a new O2 sensor. I took it back today and they told me the NOX was three times the amount allowed. The guy there told me that it might be running a bit lean :shock:. I thought it was running a bit rich, because the muffler has way too much Black dust on it. However, the smog guy told me that if it was running rich the HC #'s would be failing instead of the NOX.

Please Help, I dont know what else to do. BTW this is the 84 white mk2 - (new muffler , 2.5" pipping, new cat, DT Headers, New O2 sensor, Port and Polished Head, and cleaned out EGR system)
 

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Sure the EGR system is working? When you had the EGR valve off if you pulled vacuum on it would the valve open? The on the car test is to apply vacuum to the valve and see if the car wants to die. You can clean the EGR out like mad but if its stuck it usually will thwart any attempt to open again.
 

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Perhaps a little brainstorming here and anyone jump in if I explain this wrongly. NOX is formed when Nitrogen in the atmosphere is heated to extreme temperatures under combustion which causes it to bind with other molecules to form oxides of nitrogen. The key here is cooler combustion temps. EGR does this because there is little to no free oxygen left in the exhaust, thus its like adding a shot of inert gas. The ECU in control still maintains the correct amount of fuel for the amount of oxygen (assumed percentage of atmosphere) metered through the AFM. Are you absolutely certain the EGR system is working properly? First pull a vacuum on the EGR valve itself while idling and if the engine stumbles or dies then the valve is OK, Second, connect up a vacuum gauge with a long hose (long enough to reach into the cabin or tape gauge to outside of windshield) to the vacuum T branch leading to the EGR valve. While idling you should have zero vacuum. When you step on the gas pedal slightly, you should have 8-10in hg or so. When you lift your foot off the accelerator pedal, the vacuum gauge should snap back to zero that quick. If all thats OK, there's also a screw on the top of the TB that bleeds in air from the crankcase which also has little oxygen because its mostly inert exhaust gas that gets past the rings (tho it may have some fuel in it too). Turn it counterclockwise a quarter or half a turn or so. The idle speed will decrease slightly as the combustion temp (energy level) comes down. Retarding timing a couple of degrees will help too but as I recall, someone mentioned they check timing in California. The thing that really sux is us backyard mechanics can't afford the equipment so we could tune for emissions ourselves. Hope that works for ya.

Phil D.
 

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Phil

what you said about the NOX is the same thing the smog guy told me. NOX Temp is too high and to reduce the NOX I would have to somehow reduce the temp in the combustion chamber.

The smog guy wanted me to leave my car there so he can fix it :roll: He told me that I would probably be looking to spend around $200-$300 :shock:. There is no way Ill let a dirty mechanic touch my car if I can fix it myself (with help from you guyz that is :wink: )
 
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