Very rough idle on STOCK platform

[nawfbb]

5.3 with 4l80e swap c10
stock intake injectors everything stock besides header
BP stand alone harness
will run rough smooth out then rough again need to get second opinion im thinking ECM bad
also headers have different temps on each temperature cylinder some are 150 other at 300

[gtstorey]

If random cylinders are different temperature, it’s not a tune issue, unless you are talking about one bank vs the other. This is a mechanical/wiring issue.

[gtstorey]

And you should post in the section that applies to your ECM for more help (GM gen 3, 4 etc)