Car Shaking at idle
I got a 08 envoy 5.3 and it shakes every couple seconds at idle. But it only does it when the car has been running from a little. Doesn't do it when the engine is cold. Also my check engine light turns on & off every couple days for p0106. What could be the problem? I just got my catalytic converter replaced. Does the computer have to relearn how to run with the new catalytic converter?
Check the usual suspects (spark plugs, filters, fuel pressure, vacuum leaks). Check live data for fuel trims, misfire counts, or anything else suspicious. (I don't know if your vehicle needs any kind of reset after replacing the converter.)
You can find troubleshooting information for P0106 in the links below:
https://www.carparts.com/blog/p0106-code-manifold-absolute-pressure-baro-sensor-range-performance/
https://www.obd-codes.com/p0106
https://www.youtube.com/watch?v=HbVlsXiXLK0
Additionally, a free repair manual for your vehicle can be found at charm.li.
My friend scanned my car and said it wasen't misfiring. It might be vacuum leak because spark plugs were just changed a year ago.