Failed Emissions - High NOX - Colorado (1 Viewer)

[lazy]

My bi annual torture ritual is up this year. 2018 I had the whole exhaust redone with new cats and passed with flying colors (and the vehicle is much quieter). I would normally go balls deep into researching this, but I've only had time to read a few threads.

Results of my test

	Reading	Limit
HC	0.2498	1.2000
CO	0.1685	15.000
NOX	10.6960	3.5000

I have 4 codes
P0125 - something to do with o2 sensor
P0135 - something to do with o2 sensor
P0325 - knock sensor
P0330 - knock sensor

I think I have an electrical issue somewhere, but I don't think any of those codes are causing my NOX problem? Or are the O2 sensors tied into the EGR system? I thought it was just a temp sensor which shut off the EGR when it wasn't cold or wasn't hot....

I watched snake eaters video and I put -5 psi vac on passenger side and the engine stumbles, but I can't get it to die if I pinch off the hose on the driver side with vacuum on the passenger side. I then went full on dude "I got this mode" trying to figure out what this meant and pulled the throttle out and EGR valve out. I assumed the port was clogged, but I cleaned that out 4 years ago and it is actually in really good shape.

Does the fact that I can't get the vehicle to die with vac applied and pinching the driver side mean my EGR valve is bad? My modulator is like 6 years old (maybe 50,000 miles on it), new toyota part. Any thoughts?

 

[RayRay27]

What model year do you have first off?

 

[lazy]

96 lx450, sorry about that....

 

[gnob]

Fix the codes before you chase tail with the egr

 

[lazy]

Fix the codes before you chase tail with the egr

The codes will get fixed, but my question is are they tied to my high nox issue?

 

[Rifleman]

Code P0125 insufficient coolant temp for closed loop fuel control. If your Cruiser has registered it, it means that the ECM/PCM is getting a signal from the engine coolant temperature sensor (ECT) that the engine is not warm enough to enter closed loop fuel control. P0125 is usually caused by a bad thermostat, low coolant, or a bad ECT sensor.

Code P0135 possible causes are a bad O2 sensor, wiring harness damage, O2 sensor wiring harness terminal damage.

So yes these items can effect your emission readings.

 

[lazy]

thank you, I'll try and address those issues....

 

[lazy]

Well....I replaced thermostat, replaced ECT sensor (which was clearly broken as the terminal was free spinning), topped off coolant and found the o2 sensor had come unplugged. I cleaned the O2 sensor terminals with lectramotive and reattached. After a reboot and a quick drive (I did realize how nice it is to have your diagnostic lap around North Table Mountain and past Slee) I just have the knock sensor codes. Everyone's favorite toyota dealership on the west side of town wanted $319/sensor and I am quite certain while it may be something I want to eventually fix, the knock sensors have nothing to do with emissions (I'm happy to be corrected if that isn't accurate). Tomorrow is the last day for my "free" retest, so I am going to see what happens (2 miles from my house). If I still have the high nox issue, I may just go for the entire EGR rebuild. It should get me close enough to a waiver if I can't pass after that....

 

[ccslider]

I have some knock sensors used. Broomfield area

 

[tominboise]

When i busted both of my knock sensors, I bought one used from an ebay salvage yard and another from Rockauto. Both worked.

 

[Kernal]

O'Reillys sells a Made in Japan knock sensor for around $40. They are virtually identical to the OEM part, exact same markings. It's from O'Reillys Import Direct Line of parts (#17-0744 for 89615-30050). I installed one last year, no issues.

See photo below: used OEM on the left, new O'Reillys part on the right:

 

[brockdeck]

O'Reillys sells a Made in Japan knock sensor for around $40. They are virtually identical to the OEM part, exact same markings. It's from O'Reillys Import Direct Line of parts (#17-0744 for 89615-30050). I installed one last year, no issues.

See photo below: OEM on the left, O'Reillys on the right:

View attachment 2366918

I haven’t had any of these issues but this is seriously good to know for everyone!

 

[lazy]

O'Reillys sells a Made in Japan knock sensor for around $40. They are virtually identical to the OEM part, exact same markings. It's from O'Reillys Import Direct Line of parts (#17-0744 for 89615-30050). I installed one last year, no issues.

See photo below: OEM on the left, O'Reillys on the right:

View attachment 2366918

thanks!! ordered a set. Even got 10% off.

 

[Kernal]

Let us know when they come in if they're still the Made in Japan part.

 

[BILT4ME]

Also, pour in a bottle of gas treatment and drive it to get it good and hot right before the test.

 

[lazy]

Well....thanks for pushing me in the correct direction and applying occam's razor. sometimes when you're in the forest it's tough to be objective.

I passed on the retest today. Numbers were as follows:

	reading	limit
HC	0.5632	1.20000
CO	2.5529	15.000
NOX	1.2207	3.500

Interestingly, I was looking over the wiring diagram today and I thought the EGR system was standalone, but the VSV for EGR does seem to be controlled by the ECU.

I should have the knock sensors tuesday from O'R and I'll report back what if they're the Japanese versions.

 

[daytonadogie]

Off subject, but what happened to your LS swap?

 

[lazy]

Off subject, but what happened to your LS swap?

Been driving it a bit, although not fully legal. I set a goal to make a trip to the utah desert over thanksgiving so I've been poking away at some things. I was filling it up with gas yesterday and the gas was just pouring on the ground, so I have that to deal with now....

 

[Rifleman]

Crack in your factory gas tank, lots of threads on that subject, So instead of fixing the factory gas tank you could go for one of the aftermarket long range tanks and be done with that problem forever.

LONG RANGE TANKS FROM LONG RANGE AMERICA

I have been looking at the LRA for some time, and have started a collection of parts. One thing I can't seem to soure is the Pegasus combination tank pump switch/fuel level indicator. Any sources (including you guys)? Sorry, I am confused. You have an LRA tank? What parts are you collecting...

forum.ih8mud.com

 

[lazy]

Yeah, thanks. I went down a rabbit hole yesterday and my wife quickly pulled me out. I may just ask for forgiveness when a big box shows up....