Ok so I have a 2001 LS430 and I have done a search and have not found any specific answers to my problems. OK so like the title says, first I have a check engine light is on. I have check the codes and they are 420 and 430. So I thought it would the the O2 sensors before the catalytics and so I bought them new from Lexus and install them, cleared the codes, drove the car for about 30 mins and then bam, the check engine light comes back on and pulls the same codes. I was about to change my rear O2 sensors then the catalytic converters if I had to but I wanted to see if anyone here could help me figure out what the problem is. I really hope that it is not the cats because they are pretty pricey. Does anyone offer aftermarket direct replacement for the cats? Any info would greatly be appreciated. Oh I also noticed that my tank average has been decreasing. I only get about 14.5 -16 mpg on Tank Average.

Second problem is that my VSC light comes on only after I start rolling forward or backwards about 5 feet. Basically when I turn my engine on there is no Check VSC warning or anything. Then I start moving about 5 feet then the Check VSC words come on in the info center, my red triange with exclamation mark comes on and the my "VSC OFF" light come on. I try to turn it off but nothing happens. I also try to turn off the VSC before I start moving but the samethings happens. Anyone have any ideas what the problem could be. I would really like to get rid of my christmas lights inside the car. Thanks

Henry

 

I'll try to address your first paragraph, as with the second I don't know exactly what the VSC error conditions are for the LS430.

You have catalyst below efficiency. I would check physically the cats you have to see if any bumps or damages anywhere. A few years ago, I got a P0420, but the gas analysis was ok, just that it had a dent, and this was affecting the wavelength detected by the O2 sensor after it. Additionally, a cat can go bad. I do know of a few people who ventured into Mexico (got the gas here) and on the way back got an unpleasant suprise in the form of a CEL and they had to buy a new cat.

There are aftermarket cats such as those from Magnaflow, that do an even better job that the OEM cats, however if your cat failed and you have under 8 years/80,000 miles, whichever comes first, you should be covered under a Federal Emissions Warranty with Lexus.

When my cat went, I was already past it

 

Thanks for the info. I will check to see if my cats are dented up at all. Anyone else have any input. I really don't want to just start buying parts hoping that it will fix the problem. Thanks in advance

Henry

 

Hey Henry,
The shop was busy today so I couldn't talk to you. Have you test it yet? Let me know.
Regards,
JPI

 

Henry,

Have you fixed the VSC light on yet? What was the problem?

 

I have not fixed either problem yet, I have just learned to live with it everyday until it really bothers me then I will probably try and fix it. But if someone knows exactly what the fix is then I will probably try it.

Henry

 

I'm not an expert but this sounds like a wheel speed sensor to me. I would check all four just to make sure one did not become disconnected or even cut. If your bakes were done recently they may have been disturbed or damaged. If you were closer I would help you pull those codes but I cant afford gas to Texas.

 

If the check engine light is on the vsc light will come on because it is disabling that system so if your check engine light is on with the vsc light it is normal. If the check engine light is off then you do have an issue in that system.

 

The VSC is most likely caused by the check engine light. and your check engine light is caused by the cats. so by replacing the cats it will solve both problems.