December 13, 2023

Fix Acura RL EGR Problems Yourself : Step by Step

check engine light on Acura RL. DIY EGR issues running rough The EGR is commonly an issue we may face with our Acura RL, especially those from 1996 to 2012. It’s the troublesome exhaust gas recirculation valve, commonly known as the EGR valve. If you’ve been experiencing problems like the check engine light, rough idling, or your car just not running as smoothly as it used to, you might be facing an EGR valve issue. Let’s take a closer look DIY style.

Long StartRough idle?

Check for Recalls

Acura RL EGR Valve Issues

The symptoms. If your RL is running rough, you might see:

  1. The check engine light.
  2. OBD codes P0401 and P1491.
  3. A rough idle.
  4. Reduced fuel economy.
  5. Engine vibrations.
  6. Hesitation or stalling.
  7. Long cranking before the engine starts.
  8. Failure in state or federal smog tests.

These symptoms usually point to an EGR valve issue. The EGR valve helps reduce emissions by recirculating a portion of the exhaust gases back into the engine cylinders. But when it malfunctions, it can lead to a variety of engine problems.

Step-by-Step Troubleshooting – DIY

Get the necessary tools:

  1. A basic toolkit.
  2. An OBD-II scanner.

Scan for codes:

  1. Connect the OBD-II scanner to your RL.
  2. Look for codes P0401 (insufficient EGR flow) and P1491 (EGR valve lift insufficient).
  3. Note any other codes that may appear.

Other OBD Codes

  • P0400: General EGR System Failure
  • P0402: Excessive EGR Flow
  • P0403: EGR Circuit Malfunction
  • P0404: EGR Circuit Range/Performance
  • P0405: EGR Sensor A Circuit Low
  • P0406: EGR Sensor A Circuit High

See all the codes here.

Take a closer look:

  1. Locate the EGR valve in your engine bay. Likely the EGR valve is found on the rear of the engine, close to the firewall.
  2. Check for any visible damage or clogs.
  3. If it looks dirty, try cleaning it first.

How to test:

  1. Many EGR valves are vacuum operated. Disconnect the vacuum line and connect a hand-held vacuum pump.
  2. Start the engine and let it idle.
  3. Apply vacuum using the pump. The engine should run rough or stall if the EGR valve is opening (as it recirculates exhaust gases into the intake manifold, which is not optimal for engine idling).
  4. If there’s no change in the engine’s performance when vacuum is applied, the EGR valve might be faulty or clogged.

Acura RL EGR Replacement – DIY

  1. Disconnect the battery.
  2. Remove any components blocking access to the EGR valve.
  3. Disconnect the vacuum line and electrical connector from the EGR valve.
  4. Unscrew the bolts holding the EGR valve.
  5. Carefully remove the old valve.

Installing the New EGR Valve

  1. Clean the surface where the EGR valve sits.
  2. Place the new EGR valve in position.
  3. Reinstall the bolts, vacuum line, and electrical connector.
  4. Reconnect the battery.

Final Checks

  1. Start your RL and let it idle.
  2. Check for any unusual noises or leaks.
  3. Use the OBD-II scanner to ensure no codes are present.

Final Notes

Apart from P0401 and P1491, other codes related to EGR issues in an Acura RL might include P0402 (excessive EGR flow) and P0403 (EGR circuit malfunction).

Fixing EGR issues in your Acura RL isn’t as daunting as it seems. By following these steps, you can diagnose and possibly fix the problem yourself. Remember, a well-maintained EGR valve not only keeps your RL running smoothly but also helps the environment by reducing emissions. Stay safe and happy driving!