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2003 5.3 tripping P0135 P0141 P0161 P0171 all at the same time


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I am trying to get my 2003 Suburban back on the road from sitting. I had a rodent chew a bunch of interior radio wires while it was sitting. I tore everything out and fixed every single wire I could find. Initially it was only giving me a P0171 and an oil pressure sensor code. Since the dash was displaying 80 lbs of oil pressure before starting I replaced the sensor. 

 

Now today after like the 4th time driving the car the CEL popped on at the same time my radio started displaying that my parking brake bypass was no longer working. Based on what I found online it is almost always a blown fuse that triggers multiple O2 heater core faults simultaneously. Everything I read online tells me these trucks have O2 sensor fuses in the engine fuse block but mine has none. I pulled every single fuse from the block both in the engine compartment and in the dash and they are all good. 

 

I replaced the rear driver O2 sensor from the first time I was getting the P0171 code so I know at least that sensor was is good. Any ideas? I would think if a wire melted somewhere or shorted out that it would have blown a fuse somewhere. Any help would be appreciated. 

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4 hours ago, sefiroxx said:

Look at the Legend at bottom. You'll see O2A and O2B marked as 3 and 4. Find 3 and 4 on the map.

Thanks I didn't see that. Both fuses are good and haven't blown. I'm just confused on how I could trip 3 O2 heater core codes simultaneously and have no issues with the fuse. If a wire had burned or shorted it should have popped the fuse right? The car has been sitting for a long time. Could it be an issue with the battery? The car starts fine but the only other thing I can think of is the PCM.

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10 hours ago, silveradosid said:

all the sensors use one common ground check that ground to see if it is corroded

We live in California so not a lot of issues with corrosion. I checked all the grounds and cleaned.There weren't any issues with any of them. I put the predator on it to do data logging and with the truck idling the voltage between the 3 O2 sensors I didn't replace varied between .07 and .88 moving up and down. The sensor I just replaced on Bank 1 Sensor 2 was sitting at .05-.06 and wasn't moving. Could the new sensor be the issue or is it possible that the issue is with the PCM on that line? I checked every harness in the car top and bottom that I could see running and I didn't see any tears, frays, or anything. All I found was a 2 prong connector not hooked up to anything coming off the passenger side O2 harness, but I have heard others say they have a phantom plug too. I checked the inside cab grounds as best I could. I had the dash off doing wiring repairs and don't remember seeing anything with the ground. 

Edited by Docsls6
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1 hour ago, sefiroxx said:

Many kinds of shorts, many kinds of symptoms - only one of which is blowing the fuse. Other symptoms include slow drain, incorrect voltage signals, interfere with neighboring circuits . . .

Any thoughts then? The wires look good and it is triggering multiple O2 codes at once. I don't know if one bad sensor could cause the issue with the others. My plan is to put the old rear sensor back in and look to see if the voltage changes or remains fixed at .05-.06. If it does then I'll switch passenger side and driver's side to see if the voltage issue remains or moves with the sensor. Originally I only had one code popping up. After replacing the rear O2 I drove it for quite a while around the neighborhood and had no codes. Then boom codes and no voltage randomly but the fuses are good. 

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Sensors in front of the cat should cycle positive to negative - reflecting what the computer is doing to adjust injector opening time (more fuel/less fuel) Sensors behind will usually be stable and indicative of cat efficiency (gradual change of signal indicating slow consumption of cat metals).

If the front sensor are cycling, good but if not around 0 then they may be corroded or the engine needs work.

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