engine vibration
 

I have a 1998 k1500 5.7 my problem is there is a noticeable vibration that reverberates in a cyle felt in the gas pedal most noticeable at 2,000 rpms. The vibration is felt in park and driving. I have been getting o2 sensor codes as well. Also while cruising between 40 and 60 mph the vibration shakes the dash and steering wheel in the same cycle. I had the cap, rotor, plugs and wires replaced by a mechanic that did nothing to help the problem. He seems to think its the torque conveter? Any suggestions would be greatful!

Had a problem before similar to that. I found the flywheel cracked.