Emissions Failure

Orange Bird

Registered User
I was curious about the best place to look (repair/adjust,replace) to get my car through VA emissions. Failure was due to numbers, not visible rejection. Here is some background:

90 3.8 SC motor w 142K mi. No vacuum leaks as I sprayed points where vacuum leaks may have been present and no idle variation. Idles fine but car was sitting a while. I replaced Ign wires, pcv valve, air filter, plugs before test. One plug may have had oil on it. I am going to check it again since the car has been running for a while. After the failure I got a can of BG Fuel sys cleaner and removed a vac. hose from plenum and pulled cleaner into system slowly. Cats sound good (when you pound on the bottom) but one makes a little noise (very little) but may be grit in shield. Throttle body has slight snag in it when it starts to open.

Would posted numbers help from report?

No lights on in cluster assy.

When I pull the one plug, if it has oil again, I will try simple set of valve seals.

If no, where from there?

Cats
EGR
MAFS (mine was cleaned w/mafs cleaner and looks good b4 test)
MAP
O2's

I hate to willy nillie replace stuff.

Any ideas are appreciated.
 
Are the cat the original ones? If so, they might need replaced due to age. I had high NOX numbers (not high enough to fail) but when I put a new exhaust on the numbers went down. Also make sure the engine/cats are hot right before the test. Good hi octane fuel would be a safe bet
Good luck.
MikeH
 
Fill with premium.
Disconnect the spout connector.
Disconnect the octane connect(if connected).
This is what i have to do with mine and she passes aces.
Should pass with flying colors unless your cats are punched or it smokes,then your sol.
 
Numbers from your smog test would be nice. If you have high NOx, you probably have at least one bad cat. Changing your plugs and other things isnt going to make a difference if your cats arent doing their job.

- Dan
 
Knowing what caused the fail, HC or NOx would make all the difference, can't help much without knowing that.
 
What and or where is the 2 connectors you mention (Octane and Spout)?

They look to be original Cats. I trailered the car because I replaced the entire front end susp parts so I'm not sure if they heated up the cats before the test or not. I'll go get the sheet w/the numbers and post them shortly. New Prem fuel was put in the tank before the test as it was so low on fuel, when I loaded it on my trailer it ran out of gas while sitting on the angle of the dove tail.

I was leaning toward the cats as a starting point as they are relatively cheap. I can grab them for about 125 ea.

It does not smoke while running but it smoked like hell when I cleaned the fuel system w/the BG stuff.

Thanks.
 
Here are the numbers I have from the report. I am setting them up as the chart reads:

15MPH 25MPH
Limit Reading Result Limit Reading Result
HC ppm 72 100 FAIL 79 66 Pass
CO% 0.29 0.62 FAIL 0.42 0.51 FAIL
NO ppm 947 1990 FAIL 921 1290 FAIL
RPM 1526 Bypass RPM 1526 Bypass
Dilution 14.7 Valid Dilution 14.7 Valid

My chart looks good when I set it up but when I post the thread it crunches it back together so I will do the first line like this:
At 15MPH
HC Limit 72 Reading 100 Result FAIL RPM 1526 Dilution 14.7
At 25 MPH
HC Limit 79 Reading 66 Result FAIL RPM 1526 Dilution 14.7
 
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Looks like a bad O2 sensor or disconnected, etc.. but could also be a number of other things such as MAF, vacuum leak, etc. I would get the KOER codes before doing anything else.
 
You cannot do an emissions test without the engine being up to operating temperature AND having been driven prior to the test. If you trailered the car to the testing facility then your results are invalid. I recommend minimum 15 minute drive at operating temperature prior to testing and do not shut the engine off while waiting in line.

Pulling timing via the spout connector will help when NOx is high but won't do anything for the HC fail. There won't likely be any codes if there is no CEL. Interesting that someone would consider paying $250 for new cats without even driving the car first. I thought you didn't want to "willie nillie" replace stuff. Valve seals are not simple. Driving the car and ensuring it has a complete warm up cycle prior to showing up for testing is simple.
 
I understand the vehicle was brought up to norm op temp before testing, but I did not see it. I deal w/reputable place so I have no reason to believe they do things to make for an easy fail. Numbers are posted above. Thanks. Hard to drive car b4 test as I have invalid tags. Other repairs and work traver put me beyond 1 month temp tag stickers. I am going to try and get another month extension for test purposes if DMV will give to me. Otherwise, I may just trailer it again to test station while it idles on trailer. That said, I don't believe the numbers being that far off are attributed to the car not being driven up to test station if brought up to op temp first. I will check codes also.

If O2 sensors are bad, will that set a code?
 
Could and probably is O2 and yes they can be bad and not throw a code, that's why mechanics buy Labscopes, I got to borrow one once and saved me that hassle.

But if your not driving the car the EEC for one is not getting a setup diagnostic done, nor is the vehicle properly prepared for the test. By those numbers your cats are fine.

Though high NOx makes me lean toward dirty/bad EGR.
 
That is the kind of help I am looking for, thanks. I don't have codes according to my reader. If the DMV won't give the extended tag sticker, I will chance the ride. I get a free retest within 15 days and was also thinking about the O2 sensors. EGR is also a possibility to remove & clean. If they are not too bad $, I may replace as I simply have no time and if they are as much a PITA as I think they are, I'm not doing it twice if cleaning does not work.
 
Does the car puff out blue smoke when you start it after sitting over night? High HC but low or normal CO numbers indicate excess fuel in the exhaust. Incomplete combustion is occurring.

If you don't otherwise notice a miss (which certainly would increase HC) check and make sure you have a clear path to the engine. No animal stored something in the intake tube, and the filter is clean. Oxygen sensors tend to react slower as they age. Slow reacting o2 sensors could lead to overly lean condition when the engine runs which can lead to incomplete combustion.

A faulty cat can lead to higher HC readings, but usually you also find higher CO readings at the same time. Factory cats at that time were good for about 70k miles. Once over that, their effectiveness is reduced.

One of the issue you may of also had is if the car was sitting for a while, the adaptive controls of the EEC-IV were likely not very well tuned. It takes a couple drives of the car for the EEC-IV to really get stuff dialed in after you disconnect the battery. I'm assuming if it was stored, the battery power was lost at some time.

You might find if you just drive it around 3 or 4 times, for 20 minutes or more each time, things will clean themselves up just enough to pass.
 
Thanks again. No puff of smoke at all. It did smell a little rich but that does not seem to be a problem since I BG'd the system. I'll drive it some this coming weekend as I am getting ready to leave town and that seems to be key starting poinf from other posters as well. I know when I was working on the suspension, heater hoses, painting the inner fenders and replacing the brakes and MC rebuild the bat was disconnected about 2 months. After all the repairs, I filled w/fresh Prem fuel and ran up to the station for testing. All basic stuff was checked and no animals in air paths as it was all removed for paint as was all the IC tubes. No misses no vacuum leaks based on my test with start fluid around all areas I thought would create a miss.
 
Whatever the reason you didn't drive the car, it doesn't matter. The car has to be DRIVEN prior to testing. Idling until it gets up to temperature doesn't do anything. You have to move enough heat past the 02 sensors to get them to clear off and operate effectively. When idling it is not uncommon for 02 sensors to cool off enough that they don't read correctly, even when new. For this reason the EEC has a timer to where if it sits idling for too long it goes open loop and/or alters AFR to heat up the converters. Which brings me to the next point, if you don't DRIVE the car and put a load on it the cats may not get hot enough to operate either, especially if they are original.

I guess I assumed that was common knowledge. They have signs at our emissions stations telling you to drive the car at highway speeds prior to testing and not to shut off the motor when you pull in.

My point is not that you DON'T have a problem with an O2 sensor or a converter, but that you have no idea if you do or don't until you generate a valid test, which you have not done yet. I did not imply that the shop was shady, it's up to you to get your car warmed up enough for effective testing. If it fails a second time after proper warm up procedures, that is the time to start looking into what might be done to fix the situation.
 
I have no common knowledge of the inner workings of the test. Seems you have and after reading it seems a drive is in order - maybe a few. What you said makes sense, I knew none of that as I don't work on these things for a living, sounds like you do. That said, are you saying to drive to work 10-15 mins at 45-50 MPH then maybe take a detour on the interstate at 70 for a few (10 mi) and drop in will change my numbers enough without doing anything?

Those #'s posted above are not so far off that a simple drive would fix?

Or, centering around a drive, I go to work as stated above. Then before testing say an hour after getting to work I take that drive - say run down an exit or 2 in I95 then drop right in on a scheduled appt. Think it will pass? I could only hope life would be that simple. I will try w/o doing a thing and post results at end of week if I don't get too tied up on my business trip.
 
Your numbers are not that bad.
The spout connector is a little 2 prong termination plug near the d.i.s. module(if i remember correctly) and the octane plug is on the pass side up near the firewall where all the wiring goes through(it may not have a plug in it,it may be just open,you must run 94 octane plus to install this plug as it increase timing on the top end by 4degrees).
Believe it or not what xr7 dave says is inncorrect( i know the theory behind it)but my 89 failed all 3 numbers about the same as yours did and i thought my cats where toast.
Figuring i'd give it a shot as it would not cost me any money and the fact that i used to do e-tests years ago and helped a few hopeless cars pass by decreasing timing i tried it and,you guessed it,passed with flying colors on all 3 readings.
Take it from someone who has done it in the real world not just in theory,drive the car and get it warmed(just to the test facility and there is no need to beat the crap out of it) up but not too warm(when they run it at idle on the machine it will heat up a ton with no airflow(watched many an old ~~~ car overheat on the dyno)then before they take the car in disconnect the octane(if applicable)and the spout connector.
This will lock the timing at 10 degrees( i have seen timing reach as high as 50degrees on my standalone in my other bird at times) and way cool down the combustion chambers,while i cannot guarantee you a pass i'm pretty sure it will and it's best of all FREE.
Don't try it again without doing anything(it will still fail)at least do what i said then post the numbers(super easy 1 min fix) i guarantee they will be better.
 
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OK. I'm going to drive it some like you both say. I don't understand the octane plug and spout con. Where I am now- I put in about 7-8 gal of prem fuel (say 91 octane) I believe that's what is at my local 7-11.

I will drive to heat a few 5-10 mi cycles. Drive it to heat w/o beating I understand. I don't beat but at the same time, I don't baby - std. have fun and normal drive.

Then, pull in test facility at normal op temp.

Go to DIS and pull octane plug (or install a plug/jumper)?

Go to spout connector and do what? Am I disconnecting something here?

I will go look tomorrow. I have to come home early to play Mr Mom. Tues I fly out until Fri? we will see. If it is as simple as nailing down what you say here and following through Sat or Mon?Tues, I should be ready to drive some - legally, which works good for my job. I have so little time so I am trying to manage where it is best utilized. Sounds like it may be on the fun side - driving.
 
I thought i was pretty clear( i even read my own post again,it pretty much describes it)but here goes again.
Near the D.I.S. module(big grey module on the top of the passenger side accessory bracket)should be a small two wire connector with a grey/black plug in it(remove this plug)this is your spout connector(spark output connector,allows for electronic advance of engine timing)keep it removed for the test.
I would not worry about the octane connector(as i stated above the connector will be there but may have nothing plugged into it as from the factory they did not come with a plug installed due to some areas not having 94 octane fuel(if it does it will look identicle to the spout connector and have a jumper plug in it), it is the one up by the passenger side firewall where all the electrical connectors are.
Sorry man, i'm trying to help you out but i cannot be anymore clear than this.
If you still can't figure it out then your doomed to take it to a mechanic and pay big bucks(you may have to anyways it it fails but my method is worth a shot as it worked for me).
 
OK. I'm going to drive it some like you both say. I don't understand the octane plug and spout con.
Since your Nox numbers are fine, you don't need to remove the octane plug, nor the spout plug.

What those two things do is retard the timing so that the combustion chamber doesn't heat up as much... which is what typically causes high Nox. If I were in your shoes, I would replace the O2 sensors, drive the car around some and then take it back for testing. There's no guarantee it will pass, but since you're not getting any codes (CEL), and you noted that it seemed rich, its the place to look.
 
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