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I am having a tough time tracking down what I think is a ground short. 
I am currently testing the connector on my 4.8 for the coil packs. When I check continuity between the negative and positive terminals I get 1.653k ohms. Should I have any continuity there?
If you have the coils plugged in, you're going to have some continuity. If you suspect a short in the harness, which is doubtful since its such a small harness and taped up well, unplug all the coils first, then test it. Anything is possible I suppose.
Sorry guys, I am still trying to figure out this site. I think I need to subscribe to this thread or check it more often.
it turns out, I do not have a short. The coils were reading correctly.
However, the real issue I’m having is rough drivability, and a hesitation upon acceleration. I have been fighting PO135 and PO155 codes since I purchased this thing (heater circuit in the O2 sensors.
I checked, and I have both 12v with the key on and ground at the plug. I replaced both oxygen sensors with brand new Bosch units. I checked the pin out from the connectors to the PCM. The census are definitely reading because I can see it in my scan tool. Although the values are a little high. ( i think they want to be around .450v)
I've had terrible luck with the chinese harnesses at my shop. Usually the cost to troubleshoot them exceeds the cost of a quality harness
That said, your issue doesn't see to be in the coils but instead, oxygen sensors, specifically the heater circuits
There were two types of HO2s used over that generation of PCM and mixing them up will cause issues. There's a good explanation of the differences in here https://lt1swap.com/vortec_o2_sensors.htm
Use your meter to ohm out the harness connectors to see which it's wired for
You need to match harness type, HO2 type and PCM base file. Harness will be the hardest to adjust for, so swap the sensors and/or tune
Thanks for the help guys. I agree the Chinese harnesses are junk. If I ever build my own, I will use a quality harness. Unfortunately, for now, I am stuck with what I have.
It looks like I have isolated ground oxygen sensors. I confirmed with the guy I purchased my flashed computer from. I have a tune for a 2004 Silverado 1500 with a 4.8.
originally, I purchased these o2 sensors. But then I realized I needed female plugs connectors, not male.
after taking with the guy that flashed my computer, he thinks I need upstream sensors from a 2004 corvette. So I guess I will be getting these next. Fingers crossed, they solve my issue.
If it's yours, you can nix any part at any time
If it's a customer build you can tell them it'll be more to troubleshoot than it's worth. They can pay for a proper part or pay you to fix the junk parts
Also, you're starting at the wrong point
The harness is the hard part to change, so identify which HO2 style it's built for
It doesn't matter which sensor or tune you have right now because one/both of them are incorrect
how do you recommend I proceed? Should I not try the Ho2s for a 2004 corvette? That has the same plug that I need?
if a sensor has the same plug and four wires, does it always have a heater circuit? Are the resistance values similar in all of these Ho2s with 4 wires?
You need to identify how the harness have the O2s wired. To do that, you need to ohm out the O2 connectors against each other and to the PCM pins
EX: case on the left, isolated on the right https://lt1swap.com/01_6.0_case&isolated.gif
With the PCM unplugged (D/C your battery first) ohm the tan wires on the harness (pin A). Are they connected or not? O/L means case grd, 0-10 ohms isolated grd because they're placed together somewhere in the harness. Confirm the sensor connector to PCM pins are connected properly
Next, test the heater + circuit (pin D). Does it go to fused IGN 12v at a fuseblock (case) or to a PCM pin? (Isolated) This will relate to the trouble codes listed above
Since you're there, I'd recommend testing the high signal to PCM (pin B) and heater grds (pin C to batt -)
Once you've identified which type of sensor you need, confirm whether your existing sensors are case or isolated then move to the PCM file
unfortunately, I am a newbie when it comes to wiring so I didn’t understand everything that you described.
I know I have 12v to the heater circuit from my fuse block on a 25amp fuse. I have ground (low reference) as well. All pins at the HO2s connectors have continuity with the corresponding pins on the ECU side for a P59 computer.
Other than a high reading, the ho2s seem to be responding but their values are high. It just doesn’t seem that the heater circuits are working.
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I need help!! Ground short 
