Q: I have a 2006 suzuki grand vitara, I just recently changed the battery because it was completely dead, and now when I out it in r

This is likely an electrical issue or defective engine sensor(s). Just as a for instance, the Manifold Absolute Pressure (MAP) sensor detects engine load and generates a signal that is proportional to the amount of vacuum in the intake manifold. The ECU uses this information to adjust ignition timing and fuel enrichment relative to the amount of power needed. When the engine is working hard, intake vacuum drops as the throttle opens wide and the engine takes in more air, which requires more fuel to keep the air/fuel ratio optimized. When the computer reads a heavy load signal from the MAP sensor, it adjusts the fuel mixture to slightly more rich than normal so the engine can produce more power. The computer will then retard (back off) ignition timing slightly to prevent detonation (spark knock) that can damage the engine and decrease performance. This sequence may explain why the engine dies as you put the vehicle into gear as a load is put on the engine at that point. There are, of course, other possibilities as well. If you want the necessary diagnostic steps performed by a certified Mechanic, dispatched by YourMechanic right to your location, please request an engine stall diagnostic and the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.