Hi. Could use some advice. 94 ST Manual rebuilt engine

Previously had CEL with code 071. Replaced ERG valve, EGR modulator, and 1 vacuum hose. CEL fixed.

Went to have car smogged and all emissions are high. Here are the numbers:

15 mph HC=95 CO=0.53 NO=795
25 mph HC=82 CO=0.41 NO=763

Not sure where to begin. Should I just replace both O2 sensors to start and then retest? Any advice appreciated.

Thanks!

Jay

No one has any ideas at all??

Without knowing the limits and by how much you failed it's hard to say but just check that everything is in spec like ignition timing, plug gap, coil resistance, etc.

Probably running rich.
How old is the 02 sensor ?

I don't know that it's ever been replaced.

your NO is really high, try using 91 gas next time. also look for vacuum leaks and exhaust leaks