Failed emissions!

[trinitony]

HC and CO passed.

Oxides of Nitrogen NOx - FAILED


They indicated likely causes for high reading:

Air to fuel mixture too lean

Oxygen senor malfunction

Improper EGR

Malfunction of engine's spark advance system.

Air intake tem' too high.

Cooling system may not functioning.

Carbon deposits on the engine intake valves.

Cat ' converter may be partially clogged or not functioning properly.


Question: Will tune up (plugs, filter, wires, dist') take care of this?

 

[mabrodis]

What year vehicle and how many miles? Have you always owned it? What work has been done on it?

Without knowing any of these my guess would be the cat...but have no real clue.

 

[trinitony]

What year vehicle and how many miles? Have you always owned it? What work has been done on it?

Without knowing any of these my guess would be the cat...but have no real clue.

Oops...forgot those minor details...

94 with 147K...owned it for all of six weeks. PO (original owner ) good friend. I've known the truck from the 1st day it came off the lot. All the miles are highway miles - no off roading ever and very little city driving. Not sure on what work he has done to it...will check with him in the morning.....

 

[Pskhaat]

O2 sensors help a LOT. @147 might not be a bad investment. Run some system cleaner in your fuel, can even try a gallon or two of white fuel in the tank which burns significantly cleaner. What % off are you on emissions values?

Tune up always helps, but rarely enough to make a difference. Make sure you use low-test 85 octane fuel too, it will burn more complete if there is anything ill going on.

 

[trinitony]

O2 sensors help a LOT. @147 might not be a bad investment. Run some system cleaner in your fuel, can even try a gallon or two of white fuel in the tank which burns significantly cleaner. What % off are you on emissions values?

Tune up always helps, but rarely enough to make a difference. Make sure you use low-test 85 octane fuel too, it will burn more complete if there is anything ill going on.

5.5404 GPM CUTPOINT 4.0000

 

[Pskhaat]

Okay, so ~38% off. Relatively significant. Run some of this Toyota part# 08813-00080 for the 'whole tank. (you should drive off the whole tank, as this stuff's supposed to like to eat through fuel lines).

If you have a couple $100 to spend, do the O2 sensors, easy swap if things aren't too rusted. Spark plugs are cheap, so is cap & rotor which wouldn't hurt if they are aged at all.

The white fuel (aka coleman fuel) is an old carburetor trick that I would assume would work quite the same on computerized systems which should be able to account for the difference (but havn't honestly tried it in a latter-model vehicle). How does she ru in general?

 

[trinitony]

Okay, so ~38% off. Relatively significant. Run some of this Toyota part# 08813-00080 for the 'whole tank. (you should drive off the whole tank, as this stuff's supposed to like to eat through fuel lines).

If you have a couple $100 to spend, do the O2 sensors, easy swap if things aren't too rusted. Spark plugs are cheap, so is cap & rotor which wouldn't hurt if they are aged at all.

The white fuel (aka coleman fuel) is an old carburetor trick that I would assume would work quite the same on computerized systems which should be able to account for the difference (but havn't honestly tried it in a latter-model vehicle). How does she ru in general?

She runs swwwwweet! Starts right up and idles smoothly. No problem at Traffic lights when the change. She runs very very well I must say.

 

[landtank]

well, tuneups should be every 60k, so was one done at 120k? If not do everything, cap, rotor, plugs, wires, pcv valve and grommet, air filter, fuel filter and then take it out for a good drive to get everything up to temp and working well. I've gotten O2 CELs to go away with this sort of thing. If you still are running lean my next guess would be the 2nd O2 sensor as mine just crapped out and the truck now runs much better.

 

[RavenTai]

Do you have a check engine light? Does the 94 monitor the EGR system? I know the later 96-97 (95?) with OBDII systems do.

NOx is generated when the combustion temp goes over 2500 degree's, this is the purpose of the EGR system, it pipes in inert filler (exhaust gas) to drop the combustion temperature, the other things listed that lead to lean mixture could also cause high combustion temperature but the EGR system on the 1fz is a common problem, I would do the checkouts in the FSM, also search past threads, p0401 is the DTC for the later trucks, lots of threads about it, is there a OBDI code for the EGR?

give this a read

http://www.autoshop101.com/forms/h55.pdf

more articles here

http://www.autoshop101.com/autoshop15.html

 

[Pskhaat]

raven, can you imagine though that EGR would account for THAT high a #? Seems even a little too much for the US EGR system to compensate.

 

[trinitony]

Do you have a check engine light? Does the 94 monitor the EGR system? I know the later 96-97 (95?) with OBDII systems do.

NOx is generated when the combustion temp goes over 2500 degree's, this is the purpose of the EGR system, it pipes in inert filler (exhaust gas) to drop the combustion temperature, the other things listed that lead to lean mixture could also cause high combustion temperature but the EGR system on the 1fz is a common problem, I would do the checkouts in the FSM, also search past threads, p0401 is the DTC for the later trucks, lots of threads about it, is there a OBDI code for the EGR?

give this a read

http://www.autoshop101.com/forms/h55.pdf

more articles here

http://www.autoshop101.com/autoshop15.html

Thanks for the links! Will read them in a few....

No, I don't have any check lights...I have until May to get it corrected ..Ill be taking it to a TLC shop in a couple of weeks...

 

[loquito]

For what it is worth, there is a factory recall on o2 sensors on 94 cruisers.

 

[trinitony]

For what it is worth, there is a factory recall on o2 sensors on 94 cruisers.

Thanks!

Do you have a link, more info etc...


Funny thing happen today...wifey is so confident of the breaking on the 80..she got a $105 speeding ticket.

She drove a Durango for 3 plus years and never got a ticket..she was not confident in the brakes and drove slower...

When I ask her ..how come you got a ticket..she replies...I didn't see him....eeech...wrong answer....

 

[loquito]

Thanks!

Do you have a link, more info etc...


The recall is from ALLDATA
another member posted the link, you may have to search, I've gotten all my info from the members here. I do have the print up I did for my self.

TSB Number Issue Date TSB Title
#1 SSCS02 AUG 95 RECALL - OXYGEN SENSOR REPLACE.

I'm ganna see if it was done to my rig, I don't beleive there is a time limit. Guess I'll see.
Good luck