Where I live, there is a program called Aircare where each year before you can get insurance for your vehicle you have to go get it tested for emissions to make sure it is within regulations. I have a 1989 toyota pickup 22RE, and I failed yesterday! I have 7 days before my insurance expires to figure out what the problem is and get retested...

I failed for carbon monoxide emissions, my truck measured in at 1.14ppm and the limit is 0.7ppm. Interestingly enough, somebody cut the catalytic converter off my truck and stole it about 2 months ago so I have a brand new one.

Also, my check engine light has been on for a while now. I ran the diagnostic and got malfunction 21 - main O2 sensor signal. I replaced the sensor about 2 months ago but the check engine light hasn't gone away even after clearing the memory. The truck has no issues so I just ignored it and figured that it was a just another stupid light that doesn't work on a 21 year old truck...

I ran the diagnostic again today and it still has the same O2 sensor signal problem so I am assuming that has something to do with my emissions test failure. I don't know what else to do though???

Anybody has any ideas?