'99 Camry P0133+P0446

[elarson]

Hello, I'm new here, and new to Toyota.
I just purchased a 1999 Toyota Camry LE V6 with 130,000 miles.
The check engine light is on. The codes are P0133 and P0446, which mean 02 Sensor Malfunction and EVAP Vent Control Circuit Malfunction, respectively.

What do I do? Is one causing the other? Do I only need to replace one to make both warnings go away?

Also, the TRAC OFF light has appeared, and the "TRAC OFF" button won't turn the light off. I've searched the web and have found other people with an 02 Sensor issue and a TRAC OFF light on. They say once they fixed the O2 sensor, the TRAC OFF light went away. Is it likely that the same thing will happen for me? Is it a common issue?

[liensalebuyer]

I'm having the same 446 code on my corolla. I was told it might be a Vacumm Switch Valve. For my corolla, there is on in the engine compartment, another in the box under the gas tank above the muffler. Good luck.

[abew330]

P0133
O2 Sensor Circuit Slow Response (Bank 1 Sensor 1)

Possible Problems
Front oxygen sensor on the driver's side voltage output is slower than 1 second rich to lean or lean to rich during idling after engine is warmed up (2 trip detection logic).

Bad HO2 sensor<= Most likely
Check and fix any exhaust leaks
Check for wiring problems (shorted, frayed wires)
Check the frequency and amplitude of the oxygen sensor (advanced)
Check for a deteriorating / contaminated oxygen sensor, replace if necessary
Check for inlet air leaks
Check the MAF sensor for proper operation

Under certain driving conditions, some 1998 - 1999 model year Camry and Solara vehicles may exhibit a M.I.L. "ON" with DTCs P0440, P0441 and P0446 stored due to an inoperative Vapor Pressure Sensor. improved VSV valve to correct this condition.

P0441 and/or P0446
Possible Problems
Open or short in VSV circuit for vapor pressure sensor
VSV for vapor pressure sensor
Open or short in vapor pressure sensor circuit
Vapor pressure sensor
Open or short in VSV circuit for EVAP
VSV for EVAP
Vacuum hose cracks, hole, blocked, damaged or disconnected
Charcoal canister cracks, hole, or damaged

1. Check the VSV connector for EVAP, VSV connector for vapor pressure sensor and vapor pressure sensor connector for looseness and disconnection

2. Check the vacuum hose between intake manifold and VSV for EVAP, VSV for EVAP and charcoal canister, charcoal canister and VSV for vapor pressure sensor, and VSV for vapor pressure sensor and vapor pressure sensor. Check these hoses for correct connection, looseness, cracks, holes, damage, and blockage.

3. Check voltage between terminals VC and E2 of ECM connector (4.5-5.5 V). (replace ECM if faulty)

4. Check voltages between terminals PTNK and E2 of ECM connector while applying vacuum to vapor pressure sensor (2.9-3.7 V).

If faulty, check for open and short in harness and connector between vapor pressure sensor and ECM. If ok at this point, replace vapor pressure sensor.

If voltage above is ok, Check VSV for EVAP. When ECM terminal EVP is grounded (ignition "ON"), Air should flow in pipe E (inboard on tube) on VSV and out F (outboard on tube) on VSV (Don't use high pressure air for this test). When EVP is not grounded, air does not flow in E and out F.

5. Check operation of VSV for EVAP. Remove VSV from engine. Check that there is continuity between the two terminals (30-34 ohms). If there is no continuity, replace VSV for EVAP.

Check that there is no continuity between either terminal and body. If there is continuity, replace VSV for EVAP.

Check that air does not flow from inner port (E) to outboard port (F).

Check that air flows from port E to F when you apply battery voltage across terminals. If no air flows, replace VSV for EVAP.

6. Check the vacuum hose between intake manifold and VSV for EVAP, and VSV for EVAP and charcoal canister. Check as above.

7. Check for open or short in harness and connector between EFI main-relay and VSV for EVAP and ECM. If faulty, repair or replace harness or connector. If ok, check and replace ECM.

8. Check VSV for vapor pressure sensor. When ECM terminal TPC is grounded (ignition "ON"), Air should flow in pipe E (inboard on tube) on VSV and out F (outboard on tube) on VSV. When TPC is not grounded, air flows out G (outside of connector).

If ok, check and replace charcoal canister.

If not functioning correctly, check function of VSV for vapor pressure sensor. Remove from engine.
Check that there is continuity between the terminals (33-39 ohms). Replace the VSV if there is no continuity.

Check that air flows from port E (inboard in tube) to port G (side of connector).

Check that air flows from port E to port F (outboard in tube) when battery voltage is applied across terminals. Replace VSV if function is incorrect.

9. If good, Check the vacuum hose between charcoal canister and VSV for vapor pressure sensor, and vapor pressure sensor and VSV for vapor pressure sensor - check as above.

11. Check for open and short in harness and connector between EFI main replay and VSV for vapor pressure sensor and ECM