My 97 Blazer has intermittent idling and stalling issues. It also bucks intermittently when starting from a complete stop. It also sometimes bucks on the highway and seems unable to get enough power. If I give it more gas it seems to power through it. The check engine light has also been coming on but sometimes goes off. The codes that come up are two O2 sensors and the catalytic converter. 6 months ago my catalytic converter was blocked so I had to gut it. I haven't replaced it yet. So far I have replaced the spark plugs and wires and the throttle position sensor. I took it to my mechanic but it wouldn't act up for him even after he test drove it twice.