tbilisi79

Guy this code came coming up last half a year. I would clear it and it would go months without it.
06 gs 430.

Oxygen sensor?
Cat?

Opinions ?

SILENTM

I would start with the post cat O2 sensor first. Switch it to the other bank and see if the fault changes to the other side if it does you have a bad sensor.

tbilisi79

Thanks .

How many cats do I have ? How many oxygen sensors?

Also, if the cat was bad, wouldn't the light be on all the time. Check engine/ vsc. Has been coming on and off 3 times during the year. Each time I thought it was a dirty battery connection.
103k miles... Could the sensors be bad at this point, or a cat?

tbilisi79

Ok so 0420 is left bank.
So either one of the 2 sensors, a cat, or a cat gasket. What's weird is that the cel comes up randomly from time to time.
No funny smells, no extra noise from the cat. Car drives fine

LoveThatV8

iTrader: (1)

tbilisi79, whats your mileage on your GS if u don't mind me asking?

SILENTM

the sensors after the cat is all you need to switch. I would just do that first its the easiest and most cost effective at this point. sensor could be internally shorting out or you can check for leaks in the exhaust to see if theres a small leak right before the post o2 sensor. Sensors can go out at any time but after 100k like yours is more common. same as the cats but cats are more durable since they have to be warrantied upto 80,000miles or 8 years here in cali

tbilisi79

Guys thanks for chiming in. If the problem persists, I will start with the rear left oxygen sensor. $160 at sewell. I don't see why they are so expensive.


Car just turned 104k. This code has popes up 3 times during this year. Each time I would disconnect the battery for a minute and all would be fine .

Code comes on randomly, mostly while driving and long after I start driving, so car is warm.

First the check engine lights up, VsC soon after that.

I don't mind spending money on the car to fix the problem, just want to make sure I'm not throwing money away. There is no way I'm driving with check engine lights on.

As of now, it's off. Been 3 days.

GSteg

iTrader: (15)

I had the same issue with my car where the CEL light would be on and off. I was a few clicks away from buying a new sensor, but instead I went to get some copper RTV sealant. I spread the stuff to cover the gaps between the exhaust manifold and catalytic converter's flanges. CEL went away and hasn''t come back in 2 years. Not saying this is your solution, but sometimes it's just a simple leak that's causing the headache. I could have bought a new gasket, but didn't want to bother with the installation and waiting on parts.

tbilisi79

Wow rtf sealant ? Any special one? Temp are pretty high by the cat.

Gotcha350

If you don't want to do more work than needed or waste money on parts. Take it to the dealership or to a reputable shop with a high level scanner and pay them an hours labor to find the exact cause of the CEL.

burny

Hey brother, buy the denso O2's at Rockauto

LexLova

Low batt caused same issue for me (Vsc & trac came on intermittently also during this period), a new batt got rid of it forever. I was about to buy O2 sensors