Catalytic Converter / VSC Light Question

[OrbeaRider]

I've had the VSC and CEL lights appearing for awhile now (they both came on when I was towing a UHaul trailer). I had the CEL checked and it came back that the cat converts were faulty. Based on my reading here, I tried resetting the zero point calibration (after disconnecting the battery for about 15 minutes) and all was well for about 15 miles. Once I hit 15 miles, the CEL and VSC lights came on almost simultaneously. So, here's my question: if the cat converters really are truly faulty, would that trigger the VSC lights to come on as well? I have looked around but haven't really found an answer to that question.

The basics: 03 Sport with 138K on it.

Thanks for your help!

 

[BlackWorksInc]

When ever there is a code set in the computer on our 4Runners, it turns the MIL (Malfunction Indicator Lamp/check engine light) on and automatically illuminates the VSC, Trac Off lights as well.

 

[OrbeaRider]

Thanks BWI ... much appreciated. Guess I'll have to start looking into replacing the cat converters.

 

[MikeInNH]

Don't be too hasty into replacing the cats just yet.

The reading that says the cat is bad is from the down-stream O2 sensor. There's a very good chance the down-stream O2 sensor(s) are bad. A faulty O2 sensor will send a bad code that will mimic a faulty catalytic converter.

There are tests you can run that will tell you if it is the Cat or the O2 sensor.

If you can't run the tests...I'd just replace the O2 sensors and see if that clears up the problem. O2 sensors are a lot cheaper then a catalytic converter.

 

[OrbeaRider]

Thanks, Mike. Yeah, the O2 sensors were the first thing I replaced last year and it didn't solve the problem. My mechanic seems to think it might be really dirty cat converters and he's going to try to get them cleaned out. If he can do that, I'd rather have that done right now (at least cleaned out enough to clear the error and allow me to pass my vehicle inspection) and then keep an eye on it for a later project.

 

[MikeInNH]

If the O2 sensors were replaced...then it does sound like the cats are bad.

Sorry to hear that.

There are some good aftermarket cats that work...About 1/3rd the price of OEM cats.

 

[OrbeaRider]

Yeah, while I'm hopeful my mechanic can sort this out, I'm expecting to have to replace the cats. Although I've taken good care of my 4Runner, its been driven hard (and cross country a few times) so replacing the cats wouldn't be a shock.

 

[Hapeacres]

I had my cat cleaned and it is fine now after running for a few hundred miles. I am not exactly sure how they do it but it involves heating it up so that everything inside turns to a fine powder and then is blown out through the exhaust. All I know is I had a bat cat problem and my mechanic did this for free and there has been no problem afterwards and I avoided replacing the cat so far. Works for me

 

[MikeInNH]

Although I've taken good care of my 4Runner, its been driven hard (and cross country a few times) so replacing the cats wouldn't be a shock.

We've had a total of 4 vehicles now that have reached beyond 300k miles. And I've never ever had to replace a cat. While we don't necessarily drive them real hard....they aren't driven with kids gloves either.

 

[OrbeaRider]

Thanks, Hapeacres. That gives me some hope that my mechanic can fix this without having to go the route of cat replacement. I'm taking it in next week to have the blower motor replaced so I'll find out what he's thinking.

 

[cwhite]

Replaced Catalytic Converter...Now VSC Trac Off light is on

I just put in a new catalytic converter on my 2004 Toyota 4runner. Now the VSC trac off light is on. Mechanic could not run or find a code for reason light is on...Any suggestions? Should I be worried? Don't want to spend a lot of money on replacing parts to try to figure out the problem. Could this be a relay problem?

 

[lightfreak]

I just put in a new catalytic converter on my 2004 Toyota 4runner. Now the VSC trac off light is on. Mechanic could not run or find a code for reason light is on...Any suggestions? Should I be worried? Don't want to spend a lot of money on replacing parts to try to figure out the problem. Could this be a relay problem?

Do you have the check engine light and/or abs light as well?

If you only have the VSC lights on then you probably just need to do a zero point calibration. You can do this yourself in a few minutes . Lots of threads on here about it.
Your mechanic probably plugged in a scan tool to erase the initial check engine light and inadvertently dumped out the zero point settings in the process. Common problem with ‘03-‘04 4runners.

 

[lkinOC]

I know this question is years later as to this post, but my 2006 4Runner's cat lights come on and go off at will it seems. It is not just the VSC, but also the engine light and that picture of the car swerving. I've put in a total of 4 bottles of Cat Clean, but don't think it really works. Is there another way to figure out if it is just a sensor so that I don't have to replace a cat?

Also, is it possible to replace only one pulley or do you have to replace all three at the same time?

Thanks for any help at all.

 

[4R005]

Here's test for the downstream O2 sensor from FSM for my ( '05 LTD AWD w/V8 ). Apologies for the wriggly lines outlining sensor connector.
Assuming you have the V8 which have 2 idlers and a tensioner pulley. I release belt tension and check for bearing play by spinning/rocking pulleys. If play detected, then replace. I'm cheap so while the pulleys were removed, I pried the seal w/box cutter blade (do it from inner seal diameter, so any knicks from blade will only be at inner diameter so new grease will not be thrown out during operation ) and added a dab ( 1/3 teaspoon about )of grease to the exposed bearing race and balls. Snapped the seal back in and they were good to go.
Note; when removing tensioner pulley bolt is left hand thread.
There are folks who will replace all three pulleys while they are in there already. Peace of mind is their primary motive. Nothing wrong with that. And there are folks like me with time on their hands in spades and are happy with grease up to their elbows. The R/R of the pulleys are an easy and quick job. So you can decide.

Sorry the free hand diagram that accompanied the instructions below for testing the sensor did not load. Must have missed a step or two.













Heated O2 sensor inspection

Using ohmmeter, measure resistance between the terminals.
Terminals 1(HT) & 2(+B) - 11 to 16 ohms @ 68 degrees F
Terminals 1(HT) & 4 (E1) - 10 k ohms or higher
If resistance is not as specified replace sensor.

 

[alaskaman]

Had the recurrence for a couple months. replaced the gas cap with a non OEM and after a couple tankfuls the problem went away completely.