[Joshinator99]

Originally Posted by GTO_Gregory

Here's my two-cents.

1. In HPTuners VCM Scanner connect to the vehicle while running and look for errors. If any are listed, click on the little engine in the tool bar with the pop out label of "Diagnostics and Info." A small window will open with the DTC (fault(s) listed). Highlight the items and press the red X at the top of the menu. This will erase the fault and give you a blank slate. Scan again and see if you get the same faults. If you do, erase the faults again, then make the suggested change below to turn off the sensor.

2. Leaving a check in the box keeps the sensor enabled. Hence, it will report something.

3. If anything set the Error Mode item to "No MIL Light." This will turn off any "check engine" light from the fault.

4. Check the HPTuners forum to verify this, but you should be okay.

If Utah doesn't sniff your exhaust for carbons you should be okay.

MIL stands for Malfunction Indicator.

P0420 Catalyst System Efficiency Below Threshold (Bank 1)

p0430 Catalyst System Efficiency Below Threshold (Bank 2)

If you uncheck the SES light, your monitors will never show ready. That’s how you fail in states that plug into your ALDL port. You have to leave it checked, but set the drop down menu to “No Error Reported”.

Permanent codes will not go away on ‘17-up cars unless you’ve fixed the problem. To avoid P0420/P0430, you must set those to “No Error Reported”... *BEFORE* you install the headers! Otherwise, the permanent codes will not go away, even with a full ECM write. You would have to reinstall the OEM cats, wait for the permanent codes to clear, then set it to “No Error Reported”, then reinstall the headers. If someone is more knowledgeable about this than me, please feel free to chime in. But living in a smog nazi state (MA) has taught me the hard way. Lol

My understanding is that 2016 cars can shut the codes off afterward and just do a full ECM write, and that will erase the permanent codes. But I cannot verify that as I have a ‘17.