02 Chevy Malibu check engine light flashing

Make sure battery has a full charge and connections all good. The flashing may be because the problem might damage the cat. Any applicable trouble codes? How long since a tune-up? If it cranks good but won't start, have a helper crank it while you check for spark at the plugs. Check proper fuel pressure and fuel injector pulse. When you check fuel pressure, turn off the key and see if fuel pressure holds for a bit, if the pressure drops like a rock, you have a fuel pressure leak. Maybe fuel pressure regulator or fuel injector leaking? Smell of your crankcase oil dipstick, if it smells like gas, either you don't change the oil and filter very often or your engine is over-fueling for some reason.

Severe misfire. Do not drive car until fixed. You will toast your catalytic converters. Scan tool and fix your misfire. Coil on plug? Spark plug? Wiring? I had this recently on a customers Sienna and it was 2 coils. Denso coils fixed it. $124 parts and my diagnostic fee.