1998 Toyota Tacoma 3.4L Failed CA Smog Test. High NOx at 15mph any ideas of the problem?

No, it IS a California built Tacoma with original EGR.
I don’t know enough about what sticks they used or didn’t use or if they all had stickers. My truck did NOT come with any EGR sticker tho.

 

guess I’m confused your sticker say it cannot be delivered for ultimate use in CA so wouldn’t that be a federal emissions truck, not a CA emissions truck? Both flavors were built in Fremont, CA; but only one flavor could be sold in CA new is how I understand it.

 

My truck has CA referenced on the sticker but was originally purchased in Hawaii

 

Looks like you don't have the EGR. NOx is usually caused by high peak combustion temperatures and an EGR system can lower the peak temperatures. It could also be from over advanced timing, but the computer should control that. Maybe a lean mixture, but computer should control that. Maybe carbon buildup causing higher compression. Maybe a knock sensor not working correctly, which would detect pinging caused by high combustion temperatures and reduce the spark timing advance. If everything else (sensors, etc.) appears to work, then I guess a new cat might be your best bet.

As far as the debate over which 5VZ-FE engines had an EGR, in the 1996 repair manual in the 5VZ-FE section in the EGR section says "(2WD and 4WD/B CAB)". I'm not sure what /B CAB means. "/B CAB" is not used anywhere else in the manual. Anybody have any idea?

 

Only thing that comes to my mind is that it's a typo, intended to be DBL CAB(or something similar) maybe?

 

California Air Board if I had a guess

 

I just went out to check mine to be sure lol

 

It might be time for a new catalytic converter which will cost around $500-$600.

 

May not be relevant at all but why not. I had this issue with my 2.7 1995 Cali truck. Nox went up to the roof just 1 below the max. The original source was head gasket blown on cylinder no 1 between coolant passage and combustion chamber. Water "injection" caused computer to go nuts and reduce the amount of fuel causing lean on other three cylinders. Nox went up as well as gas mileage went up too from 21mpg to 25mpg.