While I was searching the forum for a CEL code my car spit out, I see a lot of people asking which code means what. I found a Lexus specific guide:

Lexus Specific Trouble Codes

P1100 BARO Sensor Circuit Malfunction
P1120 Accelerator Pedal Position Sensor Circuit Malfunction
P1121 Accelerator Pedal Position Sensor Range/Performance Problem
P1125 Throttle Control Motor Circuit Malfunction
P1126 Magnetic Clutch Circuit Malfunction
P1127 ECTS Actuator Power Source Circuit Malfunction
P1128 Throttle Control Motor Lock Malfunction
P1129 Electronic Throttle Control System
P1130 Air/Fuel Ratio Sensor Circuit Range/Performance Malfunction (Bank 1 Sensor 1)
P1133 Air/Fuel Ratio Sensor Circuit Response Malfunction (Bank 1 Sensor 1)
P1135 Air/Fuel Ratio Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P1150 Air/Fuel Ratio Sensor Circuit Range/Performance Malfunction (Bank 2 Sensor 1)
P1153 Air/Fuel Ratio Sensor Circuit Response Malfunction (Bank 2 Sensor 1)
P1155 Air/Fuel Ratio Sensor Heater Circuit Malfunction (Bank 1 Sensor 1)
P1200 Fuel Pump Relay/ECU Circuit Malfunction
P1300 Igniter Circuit Malfunction (Bank 1 Or No. 1)
P1305 Igniter Circuit Malfunction, (Bank 2 Or No. 2)
P1310 Igniter Circuit Malfunction (No. 3)
P1315 Igniter Circuit Malfunction (No. 4)
P1320 Igniter Circuit Malfunction (No. 5)
P1325 Igniter Circuit Malfunction (No. 6)
P1330 Igniter Circuit Malfunction (No. 7)
P1335 CKP Sensor Circuit Malfunction During Engine Running
P1340 Igniter Circuit Malfunction (No. 8)
P1345 VVT Sensor Circuit Malfunction (Bank 1)
P1346 VVT Sensor Rang/Performance Problem (Bank 1)
P1349 VVT System Malfunction (Bank 1)
P1350 VVT Sensor Circuit Malfunction (Bank 2)
P1351 VVT Sensor Range/Performance Problem (Bank 2)
P1354 VVT System Malfunction (Bank 2)
P1400 Sub-TP Sensor Malfunction
P1401 Sub-TP Sensor Range/Performance
P1410 EGR Valve Position Sensor Circuit Malfunction
P1411 EGR Valve Position Sensor Circuit Range/Performance Malfunction
P1500 Starter Signal Circuit Malfunction
P1520 Stop Lamp Switch Malfunction
P1565 Cruise Control Main Switch Circuit Malfunction
P1566 Cruise Control Main Switch Circuit Malfunction
P1600 ECM BATT Malfunction
P1605 Knock Control CPU Malfunction
P1633 ECM Malfunction (ETCS Circuit)
P1645 Body ECU Malfunction
P1656 OCV Circuit Malfunction (Bank 1)
P1663 OCV Circuit Malfunction (Bank 2)
P1780 PNP Switch Malfunction
B2785 Ignition Switch On Malfunction (Immobilizer System)
B2786 Ignition Switch Off Malfunction (Immobilizer System)
B2785 Ignition Switch On Malfunction (Immobilizer System)
B2791 Key Unlock Warning Switch Malfunction (Immobilizer System)
B2795 Unmatch Key Code (Immobilizer System)
B2796 No Communication In Immobilizer System
B2797 Communication Malfunction No. 1 (Immobilizer System)
B2798 Communication Malfunction No. 2 (Immobilizer System)

This link lists all generic codes:
http://www.obd-codes.com/trouble_codes/

 

this woulda helped me so much back then!