frequent stalling

Assuming we don't have a larger issue that was caused during the replacement like the engine is out of time, we need to start with checking for vacuum leaks using this guide:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

If there are no external leaks, then we need to monitor the vacuum of the engine by using a line off the intake manifold with a vacuum gauge.

Please see the chart below which will help with figuring out if we have the intake valves hanging open.

Lastly when you installed the cam, did you install larger injectors? If not, let's check the o2 sensor data and find out if this is lean.

If it is lean and the cam was large enough then I suspect the injectors don't have the ability to keep up with the increased amount of air in the cylinder.

Thanks so much for answering my question, i don`t remember if the mechanic kept stock injectors or used larger ones. No engine light or codes detected since work was done.

Okay. Thanks for that info. So, stalling like this is due to an air/fuel ratio imbalance so based on what was done the likely cause is the exhaust is lean meaning there is higher oxygen levels than what will keep the engine running.

The stock injectors should be able to keep up with this but if all he did was change the cam and didn't alter the PCM programming then basically the stock program will not know the cam is larger and it will not know what the issue is. That means it is not uncommon to not have codes.

Basically, it doesn't know if there is an issue and the engine just stalls.

I would highly suggest trying to find a programmer that can alter the PCM to make sure it knows this cam is installed or just find a PCM that already has this programming altered. There are many options out there.

This is all assuming we prove this out with the testing above.