* Leaking Exhaust System: This is the most likely culprit. A hole or crack in the exhaust system (pipes, muffler, catalytic converter) can allow exhaust gases to enter the vehicle's cabin. This could be anywhere from the exhaust manifold back.
* Cracked or Damaged Floorboards/Firewall: If the exhaust is leaking near the floor or firewall (the partition between the engine compartment and the passenger compartment), the fumes can enter through these weakened areas.
* Improperly Installed Aftermarket Exhaust: If you recently had aftermarket exhaust work done, it's possible it wasn't installed correctly, allowing exhaust gases to leak.
* HVAC System Malfunction (Less Likely): While less likely, a significant problem within the HVAC (Heating, Ventilation, and Air Conditioning) system could theoretically draw exhaust fumes in, though this is usually associated with a strong exhaust leak first.
What to do IMMEDIATELY:
1. Do NOT drive the vehicle. Exhaust fumes contain carbon monoxide, which is odorless and deadly.
2. Get fresh air. Get yourself and any passengers out of the vehicle and into fresh air immediately.
3. Have the vehicle towed to a qualified mechanic. Do not attempt to drive it until the problem is diagnosed and repaired by a professional. This is not a DIY fix. A faulty exhaust system can lead to serious injury or death.
This situation requires immediate professional attention. The safety of yourself and anyone else who might ride in the Bronco depends on getting this fixed promptly.
