I installed the quadrilles stealth2 a few years ago and run it stock with no dpf most of the time and in the economy mode on road trips. I recently activated my onstar services to get a bigger discount on my auto insurance. Onstar diagnostics show a code P0128, but my service engine light is not on. Any advice? Truck runs good but on long trips it does seem to run hot, sluggish throttle and higher turbo whine. Truck is an 2007.5 slt ext can 4x4. I have not changed the coolant but that is in my list to do this week.
P0128 after stealth 2
- Thread starter ST04
- Start date
P0128 thermostat, coolant is not getting to normal temps in the proper time frame the computer is allowing.
Check your ECT to see if it's getting up to about 190-200 degrees.
This usually sets a code, usually.
If you have a code scanner you'll probably find a hard code, or you had this happen before.
If you can scan and clear the code, OnStar might be reading a old hard code that was never cleared.
This has nothing to do with your Quadzilla.
Check your ECT to see if it's getting up to about 190-200 degrees.
This usually sets a code, usually.
If you have a code scanner you'll probably find a hard code, or you had this happen before.
If you can scan and clear the code, OnStar might be reading a old hard code that was never cleared.
This has nothing to do with your Quadzilla.