This needs to be stickied. It could save someone else from the hell I encountered.

[APS]

I have a fought an issue with a bone stock 2018 LTZ for a week and a half in my spare time between other appointments. This truck, nearly every time you accelerate soft from a stop after being stopped for approximately 2 seconds or longer would exhibit a torque management event at around 4 mph. Driver demand would typically go from 33% driver demand to 15% driver demand from .5sec to 1 full second and then recover with what felt like a vengeance. All tq logged items would all follow suit giving a very undesired driving experience.

What I just found this morning makes perfect sense. Having tuned this E92a T87a combo previously early this summer I was 100% focused on what it could be that I have done to cause this. The truck is completely stock and with no different changes than what I have made in no less than a few hundred gen5 trucks previously.

I have discovered that even though the parking assist is turned off collision avoidance is defaulted on. This truck was purchased by a long time customer earlier this year and apparently someone prior had covered some paint chips on the front sensors with a metallic nail polish that matches the paint. Compounding this it had a minor amount of wax and bug residue on the drivers side sensor. I had gotten very good at making it malfunction over the course of running 3/4 of a tank of fuel through it. I simply washed the sensors this morning with a soapy rag and water then I could hardly get it to do it at all and the severity was greatly reduced. My next step was to disconnect the front sensors which eliminated the fault entirely.

All though this had crossed my mind and I do have GM Techline Connect. I had scanned all systems for codes many times prior but I had not watched the live data on these sensor inputs. Here is what it looks like in a HPT log.

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