* Catalyst Converter Failure: This is a prime suspect. A failing catalytic converter can overheat, causing the internal components to break down and potentially ignite unburnt fuel. This would manifest as smoke (often white or grey) and potentially sparks as pieces of the converter break apart.
* Exhaust System Leak: A large hole or crack in the exhaust system before the catalytic converter can allow unburnt fuel to escape and ignite, producing smoke and sparks. This is more likely to cause sparks than smoke.
* Ignition System Problem: A misfire, faulty spark plug, or other ignition issue could allow unburnt fuel to reach the exhaust, where it might ignite and create smoke and sparks. This is more likely to produce smoke than sparks.
* Internal Engine Damage: Severe internal engine damage, such as a broken piston or connecting rod, can allow fuel and/or oil to enter the exhaust system, leading to smoke and potentially sparks. This is a very serious problem.
* Loose or damaged muffler: While less likely to cause sparks, a badly damaged muffler can allow hot exhaust gases to escape in an uncontrolled manner leading to smoke.
What to do:
* Do not continue driving the vehicle. Driving with smoke and sparks coming from the exhaust is extremely dangerous and could cause a fire or further damage to the engine.
* Have the vehicle towed to a qualified mechanic. Do not attempt to diagnose or repair this yourself.
* Describe the problem clearly to the mechanic. Mention the color of the smoke, the frequency and intensity of the sparks, and any other relevant symptoms.
The cause needs professional diagnosis and repair. Ignoring the problem could lead to catastrophic engine failure and potentially dangerous situations.
