Rough idle but no codes

[Payton34]

So I had a trans cooler line come off a week ago and spilled all over exhaust and undercarriage it is fixed and I was sick of the burning trans smell on the exhaust so I tried cleaning it off with brake clean. First drive after doing this once it warmed up it began idling rough at stops like was going to dye out and my exhaust stinks like rotten eggs. After 3rd cycle of turning off and on no more rough idle?  No check engine light so I have no idea what happened. Could Blake clean fouled the O2 sensor causing rotten egg smell rough idle?  I figured I would have check engine light if anything was wrong with O2 sensor

[steelerdude15]

It’s possible that a wiring harness of some sort got wet from the cleaner and caused it to act odd until it dried out. Also, the truck can store check engine codes without the check engine light coming on. If you hook it up to a scan tool, you might see a code stored.