O2 Heat Sensors

[DON TX]

Since I fixed the electrical short, I now have codes that O2 heat sensors Bank 1 & 2 Sensor 2 are bad. Where are the bad sensors located?

 

I really appreciate the help on the ground short problem. Ya'll kept me looking for ground wires and I finally found the 1 in ?00 ground wires. Of course the one I was looking for was not easily seen without taking the wire bundle on top of the engine apart and moving it around til I could see there was actually a wire and touched it to see it was loose. Thanks again.

DON TX

[00Silverado4x4]

Follow your exhaust from manifold back. There are 4 sensors total, 2 updraft (before cats) & 2 downdraft (after cats). You can't miss them, they will be screwed directly into your exhaust pipes with wires harnesses plugged into them.

[DON TX]

So do I change them all or the first 2 and which side of the exhaust is bank 1 and bank 2? I found the sensors but not sure how they are referred to. Thanks.

DON TX

[txab]

First. What are the exact code numbers you're getting? The code number will tell you exactly which sensor is setting the code. Bank 1 is the drivers side of engine, where the #1 cylinder is. bank 2 is the passenger side, where the #2 cylinder is.

[DON TX]

P0141 and P0161 are the codes. The code reader says O2 heat sensor bank 1 sensor 2 & bank 2 sensor 2 respectively. The sensor in front of pass side cat had wire bundle chaffing on the frame. It rubbed thru the cover sleeve and plastic coating on the brown wire but can't see the metal wire strand, if there is one. I taped it and positioned it so it wouldn't touch again but the codes still show after eraseing and driving

@ 5 miles. I replaced the sensor and still the codes returned.

DON TX

[TJay74]

Those will both be the after cat sensors for both sides. If the wires were chaffed I would go ahead and replace them. Be ready though, O2 sensors are notorious for being stripped/siezed in the pipes when it comes time to remove them.

[DON TX]

I replaced the sensors and they weren't seized, thankfully. I erased the codes, drove it @ 20 miles and the same codes popped back up.That's both sensors on 1 side and 1 on the other that have been replaced. Now what??? I'm not very fond of the diagnostic computers in vehicles.

DON TX

[txab]

Have you checked your cats? Maybe they're bad

[DON TX]

I will. Thanks.

DON TX

[TJay74]

The precat sensors tell the ECM what changes need to be made to keep the air fuel ratio in the correct range, the after cat sensors only the ECM if the catalytic converters are working, that is all those sensors due.

[DON TX]

Well I finally got the O2 sensor issue fixed. After 2 aft sensor replacements of the universal senors I replaced the originals with, I still had the codes come up. Sometime during all this 2 fuses were blown that protect the sensors circuit. I had pulled and checked every fuse and relay during the early stage of diagnosing the original problem of the computer ground gradually breaking off at the connection to the back of the engine block. After replacing the fuses it cleared the codes and reset after @ 40 miles and got it inspected after being expired for 1 1/2 months. I was really lucky I didn't get stopped. Any way I'm tickled I got this thing out of my frustration bucket. I also got my 2k sierra egr valve replaced and it stayed clear long enough to get it inspected. It will be interesting to see how long it stays clear. The past 4 yrs I've had to r&r it before insp. only to reappear within 2 months. Maybe it'll stay out long enough to get it sold. I will inform the lookers about the issue.

Thanks everyone for the help and support. It helps knowing some one out there is listening even if not able to help. My trucks are worked out of every day and I count on it to start up when I need it. I lose money when it ain't runnin' so I can't always wait for the mechanic.

DON TX