Typerod

Hi all, I have a CEL (now erased), code turns up to be P0053, HO2S Heater Resistance Sensor 1. My scan tool didn't mention which bank, now that I think about it. After some google searching, seems to be pointing to the heater element in the O2 sensor pre-cat. Anyone have experience with this code?

I cleared it and will monitor and report back.

Vehicle is a 2007 Tahoe LTZ; ~221,000 miles

Thanks in advance for any suggestions!

Typerod

I was just looking up prices on rockauto for a new sensor, I see there is an ACDelco Professional sensor, which costs more than the GM OEM sensor. Is ACDelco Professional better quality/reliability?

tech2

if it resets:
check the fuse
check the sensor wiring for chaffing against the frame
not sure if you can check the resistance of the heater element; if there is a spec, check it

most of the time the fault is with the sensor.

can't say which is better. I would have no issues with the oem part if its a significant price difference.

Typerod

From my google research, there was mention of checking resistance of the heater element, but it was waaay above my head, lol. I'll have to find it again, and re-read it, and try it out.

Thanks tech2! Much appreciated!

Typerod

Just an update, after clearing the code on Jan 16th, it has yet to return, hopefully it will stay that way, lol.

Typerod

Just got a text from my wife showing me the CEL is on again. Will scan it when i get home. its weird that it happened on a Monday AGAIN, lol

Typerod

P0053 and P0135 were the codes; going to troubleshoot this weekend, but most likely i'll be replacing the O2 sensor. will update soon

Typerod

So I did get around to checking the resistance on the heater of the suspect upstream O2 sensor and I was getting inconsistent readings of "OL" (open loop) or a really high resistance of like .785 M-Ohms, which is essentially an open circuit from what I have been learning. I did check for power through the fuse for the O2 sensors, I believe I was checking the correct fuse, since there are 2 fuses for the O2 sensors, it labeled something like "O2 sensor A", or something to that effect. There was power. No chaffing of the wires, or loose connections.

O2 sensor arrived today, installed about 2 hours ago, all is well for now. I had a bit of difficulty getting the sensor out, I used an O2 sensor socket, the "crowfoot" version. Here is the exact one I used:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

I also bought the deep O2 Socket, but it didn't fare too well, it was a bit too long and I couldn't get it at the correct angle, but no matter doesn't hurt to have this deep socket for future use. Be sure to let your vehicle cool off, its a very tight area where bank 1 sensor 1 O2 is, and you will most likely be resting or touching a hand/arm to the catalytic converter while reaching up to disconnect the O2 sensor connection from the engine harness. Also may be helpful to wear eye protection, to help prevent dirt and rust particles falling into your eyes.

Here is the link to a site that was extremely helpful on how to troubleshoot the O2 sensor and error codes; super informative!

Part 1 -P0135, P0155 -Upstream O2 Sensor Test (2006-2009 GM 4.8L, 5.3L, 6.0L)

I did buy the sensor from Amazon:

https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

The AC Delco part number for my 07 Tahoe is 12589321.

Good luck to whoever finds this thread! Thanks to all who provided troubleshooting suggetions to me for this issue!

*pic below is the measured resistance (.755 Mega Ohms; essentially an open circuit) of the heater in bad O2 sensor; I did measure the resistance of the heater of the new/good O2 sensor and it was 4.9 Ohms, which I believe is in the correct range, of 5 to 11 Ohms on a good sensor*

tech2

I'm betting it stays fixed

Typerod

I'm hoping it does, lol. I almost want to change out the other O2's as well. I didn't notice any increase in fuel mileage which some of my research suggested, but I did notice a tiny bit of a hunting idle which def. was not there before the R&R. The first start after the install of the new O2 sensor I did let the car warm and idle for about 15 mins, while I cleaned my tool and put away my ramps. And I when I jumped in the car to pull out of the driveway, I noticed the idle jumping a small amount. Then when I took it for a drive, when I would be waiting at a stoplight I noticed the minute idle hunting, I'm talking maybe 2-350 rpms. I can see the tachometer needle slightly jumping up and back down. I took the car out yesterday for our usual drives, about 70 mile roundtrip, and the hunting idle seems to have gone away. I was thinking maybe it was the ECM's way of adjusting to the new sensor?