My '93 LS with 212k failed smog the other day. What do you guys think the problem is?

HC 15mph - 223 (Max allowed 80)
25mph - 209 (Max allowed 45)

CO % 15mph - 3.16 (Max allowed .46)
25mph - 3.25 (Max allowed .43)


I'm guessing either Cats, O2 Sensors, or plugs?

 

You are dumping fuel , so something is not burning properly
Either an injector is stuck open
a plug is not firing , possible coil or wire
the cats only clean , they may have problems but it is not causing them .

 

check cats, replace plugs, maybe wires, after making sure they're firing in all cylinders., make sure its not running uber-rich and drowning itself.

 

I don't know if this will help I always take my lexus on the open road for about a 15 mile run then drop into the smog test place I have always passed. Several guys from the smog only told me to do this to help the car pass I was also told it helps to change your oil just before you do a smog test this one I can't say for sure if it will help. The lexus is a great built car the only repair I have done in 203,000 miles put seals in the power steering $ 25.00 and lower ball joints $190.00.

 

the fix would be to find someone to pass you for $100 lol

 

Canada has smog tests? I did not know this.

 

A multitude of possibilities

Has the car had any of these replaced? EGR, PCV, O2
When was the last tune-up...plugs, wires, cap, rotors?

 

Can you post the other gas measurments? Seeing what the other gasses are doing can help with the diagnosis.

 

Check EGR lower tube - they get cracked.