Gen 2 2018 Back Fire

[HammerCreek]

Gen 2 2018 135k miles Back Fires at 3/4 throttle. Replacing plugs alleviated for about 1200 miles. Now its back. Little bit of rough cold idle. Any ideas? No cel or codes. Shop mechanice at DTX Automotive in dallas says it might be catalytic converter? Guess it could be but seems odd to me.

 

[aandrews109]

Long shot, but my '19 did something similar at about 40k. Changed plugs and it helped but didn't cure it. Checked the intake sensors and the one at the back of the intake had a pretty good bit of oily residue on it. Got a can of cleaner, cleaned all three sensors in the intake and problem was gone.

 

[Antho]

What did the plugs look like? Thats a big factor.

 

[downforce137]

double check that gap.. if its barely too big, its going to misfire..

 

[MurderedOutSVT]

double check that gap.. if its barely too big, its going to misfire..

Giggity....