Emissions and i am puzzled.. (1 Viewer)

[BigSur]

Just got back from getting my FJ60 inspected and it failed and i can't figure out why.


Standard / Reading
HC - 179 / 89 - Passed
CO(%) - 2.22 / 3.95 - Failed
NOX - 2457 / 334 - Passed
Dilution - >6.00 / 16.45 - Passed

The only part that failed was my CO %. I have a brand new smog, used my FSM emissions manual to make sure all connections were corret. What am i missing? My cat converter is good cause if it was bad my NOX would of failed. I just installed a new muffler cause my old one had a hole and i didn't know. Would a bad muffler have caused this? I haven't gone back to retest since the new muffler install. Can someone point me in the right direction.

 

[NocalFJ60]

Have to think about this one but I think high CO readings are usually related to the carb.

-float level good?
-carb in good shape?
-PCV system good?

 

[BigSur]

The PVC is new as i replaced that when i did a major tune-up. I have maybe put 1000 miles on this truck since i bought it last Feb. Over this past weekend i put some seafoam in the carb to help clean it out. Truck runs awesome but this whole CO is bugging me.

 

[60wag]

A low NOx measurement is more an indication of proper combustion temps (your EGR is working) rather than the function of the cat. In my experience, high CO is due to a weak air injection system. While the air pump may be putting some air, they tend to be at low end of the Toyota book spec if in spec at all. There are a number of switching valves for the AI system that fail. Unless you have confirmed that they all are functional, I'll bet something there isn't working. Is the cat new? An old air pump combined with an old cat might squeak by on a two speed tail pipe test but is even less likely to pass a dyno emissions test. As a check, you can tweak the AI system to pump air directly into the exhaust and bypass the control system. See if that gets the total CO down but keep in mind you can overheat the cat by doing it.