Here are some of the most likely causes:
* Dirty or Faulty Idle Air Control (IAC) Valve (or equivalent): This valve regulates the amount of air entering the engine at idle. If it's dirty or malfunctioning, it can cause erratic idle speeds, including stalling. Cleaning it might solve the problem, but replacement is often necessary if cleaning doesn't work.
* Vacuum Leaks: Small vacuum leaks can significantly affect idle. These leaks can be anywhere in the intake system, from cracked hoses to loose connections. A thorough inspection of all vacuum lines and connections is crucial. Pay particular attention to the brake booster line.
* Dirty or Faulty Throttle Position Sensor (TPS): The TPS tells the engine control module (ECM) the throttle position. A dirty or faulty TPS can send incorrect signals, leading to idle problems. Cleaning is worth trying, but replacement might be needed.
* Mass Airflow Sensor (MAF) Sensor Issues: While less likely to *only* cause problems at idle, a dirty or malfunctioning MAF sensor can provide inaccurate readings, affecting fuel mixture and potentially causing idle fluctuations. Cleaning is a good starting point.
* Faulty Engine Control Module (ECM): While less common, a failing ECM can cause a variety of problems, including erratic idle. This is usually diagnosed last, as it's more expensive to replace.
* Problems with the Fuel System: Though less likely if it runs fine under load, issues like a weak fuel pump or clogged fuel filter could contribute to low fuel pressure, causing idle problems.
* Ignition System Problems: Weak spark plugs, worn ignition wires, or a failing ignition coil can lead to misfires, especially at idle when the engine is under less stress. Inspect these components carefully.
Important Considerations:
* 95 RPM is exceptionally low: This is very close to the engine stalling. Even a slight further drop will cause the engine to die. Address this issue immediately to prevent potential damage to the engine.
* Diagnostics: The best approach is to have a qualified mechanic or use a diagnostic scanner (OBD-II reader) to read the engine's trouble codes. This will provide valuable clues about the underlying cause.
* Safety: While driving, monitor the engine closely. If the idle suddenly drops severely, pull over safely to avoid stalling.
In summary, several factors could cause your issue. A systematic approach, starting with the most common and easily checked components (IAC valve, vacuum lines, TPS, MAF sensor) coupled with diagnostic trouble codes, will likely pinpoint the problem. Don't delay addressing this—driving with a consistently low idle is dangerous and could lead to engine damage or a dangerous situation while driving.
