Lexus Troubleshooting Questions? Ask a Lexus Expert
Hello. Welcome to Just Answer. Please allow me to assist you. The P1135 and p1155 are Air/fuel sensor codes. You need to replace the two first sensors on the exhaust system that are right after the exhaust manifolds. Use genuine Lexus sensors. Denso sensors form a parts store are not exactly the same and are misinterpreted by the fuel injection computer.
The P0171 code is a Mass Air Flow sensor issue. Most common, it is dirty inside. Remove the sensor and spray it liberally inside with aerosol Brake cleaner and let it air dry. DO not use compressed air to dry it, you will damage the sensor. Also, make sure that there are no leaks in the tube between the mass air flow sensor and the engine. Any tiny leak in this area will also cause the P0171 code.
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