p0154 code

When the van idles for more than 15-20 min, I get this code. I know it's the O2. Question is, if I swap the before and after sensors, and the code goes away, it's the sensor. If the code returns, it's the wire.... correct?

I have managed to second guess myself into confusion

I REALLY do not want to spend the $50 to replace just to find it is something else.

Year, make and model of vehicle in question please.

2004 Chevy express 3500 with the 6.0l

P0154 HO2S Bank 2 Sensor 1, HO2S voltage is hanging around bias voltage, 350mV - 550mV to be exact, for more than 60 seconds. Bank 2 is the right (passenger) side. Sensor 1 location is the pre-cat position.

Instead of swapping the HO2S from post-cat to pre-cat, swap them from left bank to right bank. I don't think the connector is the same from pre-cat to post-cat.

If the problem follows the HO2S the code will change from P0154 to P0134 HO2S B1S1 indicating a problem exists with the HO2S. If it remains on bank 2 you may have a wiring issue.

In all likelihood the sensor has failed, but never rule out wiring, as you have suggested.

Good luck.

Have you been properly welcomed to this place, gmtech? ;-)

The parts stores all have different numbers for left/right, but the same numbers before/after.

I'm thinking this is a typo.


It's going to be over 100* (heat index ~120*) this weekend, so this will wait 'till early next week.

I'm thinking this is the sensor itself as it ONLY happens after extended idle times. I can drive for hours and no code..... idle 20 min and BAM!

With 98K on the clock, is this one of those things where you replace both "just because"?

Jim, take a look at this thread....

https://gmlongroof.4umer.com/t6087-persuaded-in-oklahoma

GMPartsdirect has the 02's listed as right/left also.... rights at $42.40 and the lefts at $71.60!

Krzdimond wrote:

I'm thinking this is the sensor itself as it ONLY happens after extended idle times. I can drive for hours and no code..... idle 20 min and BAM!

With 98K on the clock, is this one of those things where you replace both "just because"?

More than likely the heater in that HO2S is going bad, it is unable to keep the sensor hot enough during the idling. If you had a scan tool you would be able to look at the amperage being pulled by the O2 heaters and would likely find it is not keeping up with the others. Believe it or not the HO2S may be getting too cold, they operate effectively at +700F and making it lazy.

HO2S don't last forever and degrade over time. So, as maintenance, yes I would replace both HO2S. With 98K I think it has served its time well.

That sucks!

Rock auto seems to be the cheapest for the OE Denso parts.