VSC TRAC/VSC OFF/CHECK ENGINE. Would like some actual answers

[Rancho5]

After lots of research on the "VSC TRAC/VSC OFF/CHECK ENGINE" I'm more confused than satisfied.

There are lots of opinions out there but not much definite data...at least not that I can find.

Here's my codes:

P0440: "The P0440 code means that the control module has detected a leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the most common cause that triggers the P0440 code."

Gas cap is snug and the gasket looks to be in great shape.

P04200420 refers to the catalytic converter or - more specifically - the oxygen (O2) sensors before and after it on the bank 1 side of the exhaust system. On most vehicles, there is an O2 sensor both in front (upstream) and behind (downstream) the catalytic converter.

If it's this, which sensor is most likely to go out?

When it first popped up I reset the codes and they were out for a couple of weeks. When it popped the second time, I reset again and the lights came on immediately

Thanks for helping a newb.

 

[jgue467]

I've not but others on here have reported leaks in the evap system beyond the cap and it's gasket, so check deeper.

P0420 is often caused by the 2nd sensor needing replacing. It can be tested, use the FSM for complete specs/procedures. If it's ok, it may be time for a new/updated cat but that should be last to be considered due to cost.

Mine will throw a p0420 almost on demand when ever I drive slowly (usually off road) - say 10mph or less for a half-mile to a mile will do it. :cowboy:

 

[gamefreakgc]

After lots of research on the "VSC TRAC/VSC OFF/CHECK ENGINE" I'm more confused than satisfied.

There are lots of opinions out there but not much definite data...at least not that I can find.

Here's my codes:

P0440: "The P0440 code means that the control module has detected a leak in the Evaporative Emission (EVAP). Loose fuel tank filler cap is the most common cause that triggers the P0440 code."

Gas cap is snug and the gasket looks to be in great shape.

P04200420 refers to the catalytic converter or - more specifically - the oxygen (O2) sensors before and after it on the bank 1 side of the exhaust system. On most vehicles, there is an O2 sensor both in front (upstream) and behind (downstream) the catalytic converter.

If it's this, which sensor is most likely to go out?

When it first popped up I reset the codes and they were out for a couple of weeks. When it popped the second time, I reset again and the lights came on immediately

Thanks for helping a newb.

Replacing the gas cap, especially if the original, is the best & cheapest thing to start with for the P0440. It's the most common leak point, even if visually it looks sound. Has to do with holding pressure.

Like the other member said, the P0420 is most likely the rear O2 sensor behind the cat has decided to quit on you. The are roughly $50 on Amazon if that helps. The differences in model numbers have to do with the wire harness length, 4WD need a longer harness. If that doesn't work your catalytic converter needs to be replaced if emissions or smog rules require to have no codes to pass the emissions test.

 

[spartacus]

SC TRAC/VSC OFF/CHECK ENGINE. Would like some actual answers

 

[Rancho5]

Looks like I’ll start with a gas cap. Where I live there are no emissions requirements at all. Zero, zilch, nada

 

[Plastics guy]

I had the identical two codes about two months ago. I bought a Gas Cap from Toyota and put in a denso O2 Sensor(downstream). No more problems.

 

[Ifirefight]

Same here, brand new OEM gas cap fixed my issue.


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[AZPartsGuy]

When I had P0440 it ended up being the vent on top of the fuel tank.

Emissions leak codes are a pain the butt.

Good luck!

 

[BrianK14]

When I had P0440 it ended up being the vent on top of the fuel tank.

Emissions leak codes are a pain the butt.

Good luck!

They are a pain in the butt. Mine was a bad VSV on the cannister. I wasn’t lucky enough for it to be the gas cap

 

[Devo9000]

They are a pain in the butt. Mine was a bad VSV on the cannister. I wasn’t lucky enough for it to be the gas cap

Aloha..,
Dad had these same codes...after working his way through ...he found it to be the actual canister itself. I think it took him 6 mos of testing and fooling with it it in spare time. Hopefully you find it sooner..,
X2 pita evap codes


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[Coastalrn]

A real head scratcher

04 runner with VSC and CEL on. No abs light. Cranks..jumps into gear HARD but stepping on gas pedal does nothing. I am fairly certain that cables were crossed when it was jumped. Could it be a fuse? The ECU? And it’s not the gas cap.....HELP

 

[chottinger]

Like others have said, I've personally solved the problem with a $10 fuel cap from autozone

 

[2ndhandyotaman]

On my old '01 t4r, I had a generic emissions code ( I can't recall the exact code number) and I had the CEL/traction control/VSC lights on. It ended up being the VSV valve outside of the charcoal canister , mine was a ball of rust w/ cracked hoses. I got a new from from Toyota ( ~$50 ) and it fixed all of the dash lights and the code went away.

 

[Rancho5]

The new gas cap came today and after clearing the codes, the lights came on again. Grrrr... Time for more expensive measures I suppose.