here is a list of all the codes for the obd 2 compliant cars
a industry standard from 97 and up a lexus standard since 94 on the
ES 300 1mz-fe engine
thanks to tem for listing this


P0100
MAF Malfunction

P0101
MAF Circuit Range/Performance

P0110
IAT Circuit Malfunction

P0115
ECT Circuit Malfunction

P0116
ECT Circuit Range/Performance

P0120
TP Position Sensor/Switch ‘‘A’’ Circuit Malfunction

P0121
TP Position Sensor/Switch ‘‘A’’ Circuit Range/Performance

P0125
Insufficient Coolant Temperature For Closed Loop Fuel Control

P0130
HO2S Circuit Malfunction, Bank 1 Sensor 1

P0133
HO2S Circuit Slow Response, Bank 1 Sensor 1

P0135
HO2S Heater Circuit Malfunction, Bank 1 Sensor 1

P0136
HO2S Circuit Malfunction, Bank 1 Sensor 2

P0141
HO2S Heater Circuit Malfunction, Bank 1 Sensor 2

P0150
HO2S Circuit Malfunction, Bank 2 Sensor 1

P0153
HO2S Circuit Slow Response, Bank 2 Sensor 1

P0155
HO2S Heater Circuit Malfunction, Bank 2 Sensor 1

P0156
HO2S Sensor Circuit Malfunction, Bank 2 Sensor 2

P0161
HO2S Heater Circuit Malfunction, Bank 2 Sensor 2

P0170
Fuel Trim Malfunction

P0171
System Too Lean (Fuel Trim)

P0172
System Too Rich (Fuel Trim)

P0174
System Too Lean (A/F Lean Malfunction, Bank 2)

P0175
System Too Rich (A/F Rich Malfunction, Bank 2)

P0300
Random Misfire Detected

P0301
Misfire Detected, Cylinder 1

P0302
Misfire Detected, Cylinder 2

P0303
Misfire Detected, Cylinder 3

P0304
Misfire Detected, Cylinder 4

P0305
Misfire Detected, Cylinder 5

P0306
Misfire Detected, Cylinder 6

P0307
Misfire Detected, Cylinder 7

P0308
Misfire Detected, Cylinder 8

P0325
KS 1 Circuit Malfunction

P0330
KS 2 Circuit Malfunction

P0335
CKP Sensor ‘‘A’’ Circuit Malfunction

P0340
CMP Circuit Malfunction

P0385
CKP Sensor ‘‘B’’ Circuit Malfunction

P0401
EGR Insufficient Flow

P0402
EGR Excessive Flow

P0403
EGR Circuit Malfunction

P0420
Catalyst System Efficiency Below Threshold Bank 1

P0430
Catalyst System Efficiency Below Threshold Bank 2

P0440
EVAP Emission Control System Malfunction

P0441
EVAP Emission Control System Improper Purge Flow

P0446
EVAP Emission Control System Vent Control Malfunction

P0450
EVAP Emission Control System Pressure Switch Malfunction

P0451
EVAP Control System Pressure Sensor Range/Performance

P0500
VSS Malfunction

P0505
Idle Control System Malfunction

P0510
Closed TP Switch Malfunction

P0550
Power Steering Pressure Sensor Circuit Malfunction

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)

These are OBD codes for pre 97 cars
except 94 and newer ES 300

1 Normal Condition.
2 Air Flow Meter signal.
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal.
5 Oxygen Sensor.
6 RPM signal (Crank Angle Pulse).
7 Throttle Position Sensor signal.
8 Intake Air Temperature Sensor signal.
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal.
12 RPM signal.
13 Knock Control CPU (ECM).
13 RPM signal.
14 Turbocharger Pressure.
14 Ignition signal.
21 Oxygen Sensor.
22 Engine Coolant Temperature Sensor signal.
23 Intake Air Temperature Sensor signal.
24 Intake Air Temperature Sensor signal.
25 Air-Fuel Ratio Lean.
26 Air-Fuel Ratio Rich.
27 Sub Oxygen Sensor signal.
28 No. 2 Oxygen Sensor signal.
31 Air Flow Meter signal (Vacuum Sensor signal).
32 Air Flow Meter signal.
34 Turbocharger Pressure signal.
35 Turbocharger Pressure Sensor signal.
35 HAC Sensor signal.
41 Throttle Position Sensor signal.
42 Vehicle Speed Sensor signal.
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication.
83 TCM Communication.
84 TCM Communication.
85 TCM Communication.

Now if you need a code read there are a few ways.

1. go to NAPA, autozone , PEPboys , jiffy lube ,mr. lube or anotehr local parts store .Most of them will always give you a free quick scan if asked to get the codes.

2.buy a code reader ever car since 97 until now use OBD2 compliant scanners.So every car you own can benifit from this tool which can save you headache by knowing what is happening and getting proper advice on here about its repair or to make sure you mechanic is not ripping you off.To me the last part is worth its weight in gold and any obd2 scanner can be bought as they are all exactly the same kind of like spoons, they look slightly different but serve the same purpose no matter what.
Another option is to get a peripheral link if you have a handheld computer or laptop which can scan the codes as well and some will also data log some of the parameters to give more defined info.

3.Go to the dealer and get it read ,some do it for free.

4.I am not a fan of shorting pins and openly am telling you not to do it,but at your own risk here is the info to take a paperclip and the dash CEL will flash to correspond.

How to clear the store codes and turn off the CEL
Pin locations
Trac system codes