Eng light

[rz470]

Engine light , vsc’ Vsc trac came on all together , what is going on

 

[JLee]

Pull the code.

 

[HomersCanyonero]

My CEL and the VSC Trac lights have been coming on. When I pull the codes, I get P0171 and P0174. I clear them and they come on anywhere between 20 miles and 500 miles.

For me, Common Problems That Trigger the P0171 and P0174 Code:

1. PCM software needs to be updated
2. Vacuum leaks (Intake Manifold Gaskets, vacuum hoses, PCV hoses, etc.)
3. Mass Airflow Sensor (MAF)
4. Plugged Fuel Filter or weak Fuel Pump
5. Plugged or dirty Fuel Injectors
6. Air Intake Control Valve No 2; Toyota Part # = 17320-0A010

Anyways, you need to use a scan tool to pull the codes. Go to AutoZone and I think they pull codes for free.

 

[Dirtybird]

I thought when they all come on together it was a loose or bad gas cap?

 

[JLee]

I thought when they all come on together it was a loose or bad gas cap?

The three VSC/TRAC lights will always come on with the CEL, regardless of the cause.

 

[HomersCanyonero]

Yup all 3 come one when a code is thrown...any code. The maintenance required light is a bonus in this picture. It wants new oil but not time yet

 

[tlin]

Get a new gas cap - inexpensive if that's not the remedy but same scenario for me and that's what it turned out to be over a year ago.

Sorry, I did have codes at the time but don't remember them to tell if they were the same.

 

[HomersCanyonero]

The OP hasn't posted his codes, but as far as my P0171 and P0174 codes...I got a brand new Toyota gas cap 4 months ago. It's not the gas cap in my case. Lights come on at altitude when I'm in the mountains or when idling for a few minutes.

 

[tlin]

The OP hasn't posted his codes, but as far as my P0171 and P0174 codes...I got a brand new Toyota gas cap 4 months ago. It's not the gas cap in my case. Lights come on at altitude when I'm in the mountains or when idling for a few minutes.

Well at least you got a new gas cap....so there's that .

 

[rz470]

I just had Auto zone pull the code it says
P0430 catalyst Sysytem efficiency below threshold (bank 2)
question : bank 2 is on passenger side is it the "Air fuel ratio Sensor" close to manifold before cat and is it different kind of sensor than the one that is down after the catalytic ?
question 2: should I change the sensor first to see if it solves the problem or how could I find out if catalytic converter is bad ?
the vehicle has 218000 miles on it .thank you

 

[rz470]

I have decided to change all four sensors .which brand is better ? Auto Zone has the bosch brand and there is Denso on amazon but it seems they only sell the down stream sensor and not the A/F.

 

[bigredmachine]

denso or ngk for the o2 and a/f sensors.

 

[HomersCanyonero]

I don't remember the exact code that I got back in March 2017, but I think it might have been P0430. I opted to replace both downstream O2 sensors with new Denso ones from Amazon. My code went away and I was able to pass smog. That code hasn't come back in 10k miles. I did not replace the upstream O2 sensors.

Start replacing the cheaper stuff first and then replace the expensive stuff.

 

[rz470]

There are few O2 and A/F sensors from Denso on Amazon which it says it fit the GX I know it is long shot but can any body recall what are the parts Number . I have to say this lights coming on dash like a Christmas tree and remind me of how expensive it could get differently put a damper on my excitement of building another GX .

 

[JLee]

There are few O2 and A/F sensors from Denso on Amazon which it says it fit the GX I know it is long shot but can any body recall what are the parts Number . I have to say this lights coming on dash like a Christmas tree and remind me of how expensive it could get differently put a damper on my excitement of building another GX .

I would use RockAuto to find a part number (their search tools are much better) and then price that part number on Amazon.

 

[HomersCanyonero]

This post has a diagram with the part # for both the upstream and downstream O2 sensors

Question on Downstream O2 sensors left vs right

 

[rz470]

I look up the RockAuto for catalytic converter there are few brand such as Davico ,Dorman ,eastern catalytic,walker,bosal ,pacestler .Does anybody have any suggestion which one is a better brand or works with GX .thanks

 

[HomersCanyonero]

Denso is the OEM

 

[HomersCanyonero]

Oh wait....I thought you were asking for the O2 sensors. You are asking for the catalytic converter itself. I don't know which one is OEM

 

[rz470]

On a v8 lexus engine cylinder one sitting in the front of the engine on the driver side and that is called bank one am I correct ?