I have two problems. I'm having trouble with acceleration when the outside temp hit around 80 degree F. If I give it too much gas the engine revs., but slow acceleration as if the Catalytic Converter was clogged. I just removed the Catalytic Converter and straight piped the exhaust system. At firstI though it was the converter, but this problem still exist before and after the converter was removed. Also, the service engine light was on and stated: EVAP Leak and O2 Sensor, so I was advised to replace thegas capand O2 and I did but still proble exist. I just had work done on my transmission at the dealer, so I don't think its the trans; however, I'm getting vibration when I hit speeds above 50mph. I put the trans in nuetral to see if I had a balance problem and no sign of problems. Could this be my U joints? Maybe its time to get another vehicle.

2001 Chevy Blazer
4.3L Vortec
Mileage: 210,000

 

This definitely sounds like a transmission issue. If the engine just revs without a corresponding increase in speed (assuming a gear change or TC unlock did not happen), then the transmission is immediately suspect. A plugged cat would show signs of resisting higher RPM loads.

What were the exact codes (Pxxxx) that were present?

Vibrations can be caused by numerous things. Tim (hanr3) created a thread awhile back on the causes of vibrations - Vibrations

Let us know on the codes.

 

The codes were P0420 - Catalyst Efficieny Low Bank 1 and P0446 - EVAP purge vent solenoid circuit condition