Went to get my 89 TTA tested today and it failed. I used the "guaranteed to pass". The car is mostly stock except for 37 LB inj., torque converter and TurboTweak chip.

Reading Limit
HC GPM 1.34 2.25 PASS
CO GPM 30.64 23.74 FAIL
MOX GPM 1.67 3.25 PASS


My plan of attack is to order a TT emissions chip, change oil, lower fuel pressure,new plugs and then re-try. The O2 is a delco and is about 1.5 years old.

I wanted to see if this was good plan before proceeding????

 

High CO is either too rich, a miss, or a bad cat.
Your CO is high enough to suggest something is broken, like the cat, especially if you're not getting a SES light.
A sluggish O2 sensor can cause this, too.
I'd look for a miss, first. Then the O2 sensor, especially if you have a spare, then look hard at the cat.