02 Mazda 626 automatic tachometer rockets to 4000 rpms at first few gears engine light has come off and on what gives?

There are a few possibilities for why your 02 Mazda 626 automatic tachometer is rocketing to 4000 rpms at first few gears and why the engine light has come off and on. Here are a few things that could be causing these issues:

1. Idle Air Control Valve (IACV) issues. The IACV controls the amount of air that bypasses the throttle valve when the engine is idling. If the IACV is faulty or clogged, it can cause the engine to rev too high at idle and at first few gears.

2. Throttle Position Sensor (TPS) issues. The TPS sends a signal to the engine's computer that determines the position of the throttle valve. A faulty TPS can send the wrong signal to the computer, causing the engine to rev too high or too low.

3. Mass Air Flow (MAF) sensor issues. The MAF sensor measures the amount of air that flows into the engine. A faulty MAF sensor can also cause the engine to rev too high or too low.

4. Transmission issues. A faulty transmission or torque converter can also cause the tachometer to rocket up at first few gears.

It's important to have your car diagnosed by a qualified mechanic to determine the exact cause of the problems you are experiencing. They can then perform the necessary repairs to get your car running properly again.