So i failed my emission today....high in NOx

[akito]

I work at toyota and i had the inspector put my car in the dyno today for my emission and i failed the NOx test at 15mph. Everything pass at 25 MPH and my car failed at 15MPH because my NOx number instead of being 1200 it was reading 2283...almost double the limit!!! There are no codes and the engine light is not on. Are there any tips that i can bring this NOx number down to a less leaner reading? I thought my EGR valve is bad or my cat is clogg. Anything is appreciated. Thanks

 

[suprastanger507mgte]

HEat will also create high NOx. Is your engine running hot? Cooling system efficient?

 

[Merlyn]

Main problem with NOx that I have found is a bad EGR. Try to run the car cold, also fix your EGR. I cut my EGR off an old car and I spiked from it and failed due to NOx (sold the car 2 months later)

The whole purpose of an EGR is really for NOx, also try running lean (if you are able to)

 

[Tun_x]

put a gallon of methanol in with a full tank of gas .. I personaly gaurantee that you will pass

 

[akito]

^^^ Really!!! I might remove the thermostat and let coolant run through it at all time. I'll see what happened then, but thanks for all the input. I had check my EGR and also did a vacum check on it, it was fine. I will try to fix all these one by one and see what happen.

 

[Poodles]

the EGR ports like to clog with carbon over time as well...

 

[thesupe87]

I just failed the same thing, only it wasn't as high was yours. This supra always just barely passes, except this time it failed. Here are my numbers in CT:

HC
Limit: 167
Actual: 18

CO
Limit: 0.53
Actual 0.02

NOx
Limit: 1167
Actual 1453

Everything is perfect, except the NOx levels. I think I might need a new cat, the car is starting to smell like the cat isn't doing it's job anymore. I have a small leak in the pipe that goes into the cat also. What do you guys think? The car has been idling great, I get 22 mpg highway even.

 

[Mr.PFloyd]

lol the methanol trick owns. lol.

 

[supraguy@aol]

the EGR ports like to clog with carbon over time as well...

AMEN!- This happened to me- low CO, high NOX. The EGR should be removed, and you need to clean out the piping. I used carb cleaner, as well as a piece of braided metal wire in a drill chuck to roto-rooter the gunk in the small metal vacuum port tube, as well as the main metal exhaust bypass pipe.
Instant near-zero emissions.

 

[Poodles]

I found it clogs pretty bad right at the opening because of the oil vapor in the IC pipes...

I saoked my intake in chemdip (think professional grade carb cleaner) you wouldn't believe the crap that came out...

 

[thesupe87]

Sounds like I gotta figure out where my EGR is located. Anyone got a pic? I have to hit up the TSRM.

 

[Poodles]

EGR valve is that nasty rusty thing at the back of the intake manifold