Lexus Running Rough

Jan. 11, 2022

Some 2014-2017 Lexus GX 460 vehicles may exhibit an engine running rough and a light hesitation under acceleration.

Some 2014-2017 model year Lexus GX 460 vehicles equipped with the 1UR-FE engine may exhibit a warning light on with diagnostic trouble code (DTC) P006A (MAP – Mass or Volume Air Flow Correlation Bank 1). Some vehicles may also exhibit the engine running rough and light hesitation under acceleration. The condition may be caused by debris in the exhaust gas recirculation (EGR) assembly.

Using Techstream, confirm that the DTC is present. 

If the DTC is present, check that the positive crankcase ventilation (PCV) hose is connected and not damaged. Repair as needed.

Check the intake system for vacuum leaks.

With Techstream connected to the DLC3, turn the ignition switch on. Enter the following menus: Powertrain/Engine and ECT/Data List/All Data/MAP. Read MAP value with the ignition on. The standard value is 80-110 kPa. If the value is incorrect, replace the manifold absolute pressure sensor.

Replace the EGR valve assembly.

Start the engine and warm it up until the engine coolant temperature reaches 167 degrees or more.

Drive the vehicle at 37 mph for five minutes or more.

Idle the engine for 30 seconds or more.

Confirm that there are no driveability concerns and that there are no pending DTCs.

P/N                                        PART

25620-38240............EGR valve assembly

25627-38020............EGR valve gasket

25628-38020............EGR inlet gasket

About the Author

Information courtesy of Mitchell 1

Information for Technical Service Bulletins comes from ProDemand, Mitchell 1's auto repair information software for domestic and import vehicles. Headquartered in San Diego, Mitchell 1 has provided quality repair information solutions to the automotive industry since 1918.

About the Author

Mike Mavrigian | Motor Age Editor

Mike Mavrigian has written thousands of automotive technical magazine articles involving a variety of  specialties, from engine building to wheel alignment, and has authored more than a dozen books that crisscross the automotive spectrum. Mike operates Birchwood Automotive, an Ohio shop that builds custom engines and performs vintage vehicle restorations. The shop also features a professional photo studio to document projects and to create images for articles and books.

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