'94 FZJ80 Failed Emissions (1 Viewer)
- Thread starter Kungpaodog
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Skrewball
TLCA#18502
Guessing Colorado has 4 wheel dynos for the testing...
Do they test at two different speeds and loads? That is what they do here in VA.
O2s are never a bad idea if you haven't done them in a few years or they are original, but it doesn't sound like your problem.
Having all the numbers for HC, CO, and NOx would be helpful. Can you post what all the numbers are, even if they are below the limits?
Usually high Nox are caused by lean conditions, faulty EGR, or faulty CAT.
If you have High HC, CO, and NOx most likey the CATs are bad.
Do they test at two different speeds and loads? That is what they do here in VA.
O2s are never a bad idea if you haven't done them in a few years or they are original, but it doesn't sound like your problem.
Having all the numbers for HC, CO, and NOx would be helpful. Can you post what all the numbers are, even if they are below the limits?
Usually high Nox are caused by lean conditions, faulty EGR, or faulty CAT.
If you have High HC, CO, and NOx most likey the CATs are bad.
- Thread starter
- #23
Yes, we have 4 wheel dynos run at different speeds and loads. They go through a whole range of speeds (mph): 20, 25, 20, 25, 30, 0, 25, 20, 25, 15, 25, 45, 50 hold, 0. That's what my emissions report shows.
HC 0.67 max: 2.00
CO 17.57 max: 20.00
NOx: 6.06 max: 4.00
Remember, these numbers were shortly after resetting the computer and only about 3 miles from my house, so they might not be optimal.
The good news is I got an O2 code today, so I'm going to order a sensor. Does my '94 have only one O2, or is there a second one somewhere I can't locate?
HC 0.67 max: 2.00
CO 17.57 max: 20.00
NOx: 6.06 max: 4.00
Remember, these numbers were shortly after resetting the computer and only about 3 miles from my house, so they might not be optimal.
The good news is I got an O2 code today, so I'm going to order a sensor. Does my '94 have only one O2, or is there a second one somewhere I can't locate?
Jacket
Moderator
Here's 20 pages of getting 80's to pass emissions in Colorado.
http://www.risingsun4x4club.org/forum2/showthread.php?t=10919
Aside from the parts that have already been mentioned, I like to load up on 91 octane (premium around these parts), bottle of Heet, and make sure the wagon is good and hot by the time you get on line (and it would be great if you didn't sit on line at the testing station for 45 minutes).
http://www.risingsun4x4club.org/forum2/showthread.php?t=10919
Aside from the parts that have already been mentioned, I like to load up on 91 octane (premium around these parts), bottle of Heet, and make sure the wagon is good and hot by the time you get on line (and it would be great if you didn't sit on line at the testing station for 45 minutes).
Skrewball
TLCA#18502
With those numbers you do have a mixture problem. It does look like O2s would be a good start. Your 94 has two sensors. They should be side by side right in front of the cats.
Check for any exhaust leaks before the O2s.
With the high CO and NOx the engine is probably running lean. This is incorrect as pointed out. Keeping this so the thread stays complete.
Usually if there is an egr problem, the NOx numbers fluctuate during different parts of the test.
If you also had high HC it would look like you'd need cats too.
Check for any exhaust leaks before the O2s.
With the high CO and NOx the engine is probably running lean. This is incorrect as pointed out. Keeping this so the thread stays complete.
Usually if there is an egr problem, the NOx numbers fluctuate during different parts of the test.
If you also had high HC it would look like you'd need cats too.
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Not CO. It is the reverse: Lean = low CO; rich = high CO
- Thread starter
- #27
From what I've read, I believe Pin Head is right about CO.
RE: O2 sensors: crap. I ordered one. I guess I need to order one more for my '94, and I should do better research before ordering parts. D'oh!
Thanks for all the help to all of ih8mud. You guys rock.
Might want to climb underneath the truck and check the o2 sensor plugs for water/corrosion.... I would get rich/lean codes with mine or the truck would run funny, all traced to water/corrosion in the plug...
I am not sure about Colorado, but I disabled all of my emissions items except for the cats and relocated my o2's to the PAIR ports and it has no problems passing the emissions test. (Low and high idle, no dyno)
I am not sure about Colorado, but I disabled all of my emissions items except for the cats and relocated my o2's to the PAIR ports and it has no problems passing the emissions test. (Low and high idle, no dyno)
Skrewball
TLCA#18502
I guess saying CO = rich/lean isn't always a definite thing. Basically high CO is caused by inefficient combustion.
I had said lean for a couple reasons.. If it were rich the HCs would also be high or near max. Also rich mixture reduces NOx. I was incorrect about the lean mixture causing high CO.
After the new O2s and a retest, I'd be curious to see the numbers!
I had said lean for a couple reasons.. If it were rich the HCs would also be high or near max. Also rich mixture reduces NOx. I was incorrect about the lean mixture causing high CO.
After the new O2s and a retest, I'd be curious to see the numbers!
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It is unclear (to me anyway) whether the denso o2 sensor part sold by worldpac (partsgeek is just a worldpac dealer) is one sensor or a kit of two + gaskets and hardware.
The toyota p/n is a whole kit.
As for deleting PAIR, in utah that may cause you to fail visual inspection. I presume denver is a stricter regime.
Skrewball
TLCA#18502
I edited my posts to keep the thread intact, but to make sure my false info isn't followed.
You are correct, but you knew that already!
I factory cats are bolted together but bolts will be rusted. I replaced all my bolts for the cats and heat shield with SS bolts, they come apart easy now.
O2's only last me about 100,000 miles.
When I go for the Colorado Front Range emission dyno test I plan on doing the following:
Air tires to almost max pressure
Remove air filter (my O2 sensors are unplugged do to they wore out again, I assume with the motor is running a bit rich with no O2's so more air flow might help???)
Remove front drive shaft and lock T-case ( should put less stress on engine, I assume that the dyno puts resistance on the drive train???)
Put some sort of insulation around the cats under the heat shield to keep cats hot
Mix some E-85 in the gas tank (see internet tricks for emissions) denatured alcohol is suppose to help too
Fresh oil and oil additive (my motor smokes on startup and uses some oil while driving)
The only thing I need to fix egr is new temp sensor, may try and find a used one.
Not sure if OD and ETC will help or hinder but I would assume that lower rpm"s with = less emissions but thats just a guess. Not sure if the 1FZ motor runs cleaner at high rpm's or at low rpm's.
O2's only last me about 100,000 miles.
When I go for the Colorado Front Range emission dyno test I plan on doing the following:
Air tires to almost max pressure
Remove air filter (my O2 sensors are unplugged do to they wore out again, I assume with the motor is running a bit rich with no O2's so more air flow might help???)
Remove front drive shaft and lock T-case ( should put less stress on engine, I assume that the dyno puts resistance on the drive train???)
Put some sort of insulation around the cats under the heat shield to keep cats hot
Mix some E-85 in the gas tank (see internet tricks for emissions) denatured alcohol is suppose to help too
Fresh oil and oil additive (my motor smokes on startup and uses some oil while driving)
The only thing I need to fix egr is new temp sensor, may try and find a used one.
Not sure if OD and ETC will help or hinder but I would assume that lower rpm"s with = less emissions but thats just a guess. Not sure if the 1FZ motor runs cleaner at high rpm's or at low rpm's.
- Thread starter
- #34
Good info.
I don't know that removing the drive shaft would be worth the effort, but I don't think it would be a reason to fail the visual test. Make sure you don't throw any codes with the O2s unplugged.
In general, an engine runs best near it's torque peak, but I don't know if that means lower emissions. I would guess that OD off and ECT (power!) on would be best to pass emissions with larger tires, but I have no data to base that on.
Colorado doesnt care if you have the CEL on for its test. http://aircarecolorado.com/fail-and-repair-information/check-engine-light/
For the Colorado emissions test, the tester has to keep your vehicle speed up to certain speeds. I would assume there is some resistance applied to the rollers to see how the motor works under a load.
The last time I tested the tester had a hard time keeping up to the speed needed to pass the test. I later found that I forgot to hook up my transmission cable to the throttle body which downshifting a problem thus making it hard for the tester to increase speeds to match what the dyno wanted the vehicle speed to be. The 80 would downshift too late thus the motor was lugging in a higher gear all the time. Not sure if a lugging motor would be better or worse for emissions testing.
As for removing the front drive shaft, if there is resistance applied to the dyno rollers, then there would be about half as much resistance to the motor if you only had resistance to the rear wheels. IF there is no resistance applied to the dyno rollers, then I would assume removing the front drive shaft would be a waist of time.
For the Colorado emissions test, the tester has to keep your vehicle speed up to certain speeds. I would assume there is some resistance applied to the rollers to see how the motor works under a load.
The last time I tested the tester had a hard time keeping up to the speed needed to pass the test. I later found that I forgot to hook up my transmission cable to the throttle body which downshifting a problem thus making it hard for the tester to increase speeds to match what the dyno wanted the vehicle speed to be. The 80 would downshift too late thus the motor was lugging in a higher gear all the time. Not sure if a lugging motor would be better or worse for emissions testing.
As for removing the front drive shaft, if there is resistance applied to the dyno rollers, then there would be about half as much resistance to the motor if you only had resistance to the rear wheels. IF there is no resistance applied to the dyno rollers, then I would assume removing the front drive shaft would be a waist of time.
itbrokeagain
SILVER Star
We got rid of emissions testing a few years ago. Thankfully. But when we did have it I think they rolled the vehicle and plugged something into the obd2 port. If there was a cel they wouldn't test. I did t have my 80 but my mom had a 96 back then. It got a high idle test. They didn't put it on rollers
- Thread starter
- #37
I'd be pretty angry if they rolled my Cruiser over just to check emissions
OBD2 doesn't apply in this case since '94 Cruisers are OBD1, and I don't think they plug in the computer to OBD1 systems during testing here. Can anyone verify that?
- Thread starter
- #38
Good link. I saw the spot on the test report for the CEL and I assumed since it says "pass" that the alternative is "failed." Good point on the drive shaft, too. Maybe if I'm feeling cheap and I need to pass I'll try that!
I'd be pretty angry if they rolled my Cruiser over just to check emissions
OBD2 doesn't apply in this case since '94 Cruisers are OBD1, and I don't think they plug in the computer to OBD1 systems during testing here. Can anyone verify that?
Correct. Nothing to plug into.
few things to think about... high NOx is from higher combustion temps. How is your temp gauge reading - normal-maybe a little higher? could be issues related to cooling.
high co is as said= rich mixture. We'll see how this helps with your new O2 sensors.
I believe Co and Nox combine in the cat to reduce both - but they should already be lower even before they even enter the cat.
high co is as said= rich mixture. We'll see how this helps with your new O2 sensors.
I believe Co and Nox combine in the cat to reduce both - but they should already be lower even before they even enter the cat.
