Potentially Inexpensive Repairs (under $200):
* Spark Plugs/Wires: Worn or damaged spark plugs and wires are a common cause. Replacing these is relatively inexpensive, but labor costs will be added.
* Loose or Damaged Connectors: A simple loose connection on a wire or sensor can cause a misfire. Diagnosing this is often the cheapest part.
* Vacuum Leaks: A leak in the vacuum system can disrupt the engine's air-fuel mixture. Finding and fixing this leak could be straightforward.
Potentially Expensive Repairs (over $200, potentially much more):
* Ignition Coil(s): If a coil is faulty, it needs replacement. The cost depends on the number of coils (one per cylinder or multiple coils for multiple cylinders) and labor.
* Mass Airflow Sensor (MAF): A faulty MAF sensor provides inaccurate readings to the engine computer, leading to misfires.
* Fuel Injectors: Clogged or failing fuel injectors can prevent proper fuel delivery, causing misfires. Cleaning injectors is less expensive than replacement.
* Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP): These sensors are crucial for ignition timing. Failure can lead to misfires and is more expensive to replace.
* Engine Control Module (ECM): In rare cases, a faulty ECM might be the culprit. This is a very expensive repair.
* Worn Valves or Piston Rings: This is a significant mechanical problem requiring extensive engine work, potentially involving a rebuild or replacement. This is the most expensive scenario.
To get an accurate cost estimate:
1. Get a Diagnosis: Take your Mercury Mystique to a qualified mechanic for a proper diagnosis. They'll use diagnostic tools to pinpoint the source of the misfire. This diagnostic step is crucial before any repairs are attempted.
2. Get Multiple Quotes: Once you know the problem, obtain quotes from several reputable mechanics to compare prices.
3. Consider Parts Sourcing: You might save money by purchasing parts yourself (like spark plugs) but be sure the mechanic will work with parts you supply.
Without knowing the exact cause of the misfire, it's impossible to give a precise cost. The total could range from less than $100 to several thousand dollars. A proper diagnosis is the first, and most important, step.
