[Donjazz]

So I have a 2022 LT1 Manual 26K miles that I purchased used a couple months ago. I've had two F bodies back in the gap, a 2010 V6 Camaro and now this fella. I like it and think of the LT1 as the formula from back in the day. I've had some 5.0's too and I have to say that the Tremec blows away the mustang Getrag tranny (miss shift city under WOT with the pony). Anyway, so the car has somewhat of a rough idle whether its cold or warmed up. Also, when I'm cruising between 1500-2000 rpm around 30-40 mph ish it feels like its missing alittle. I cleaned the MAF with CRC cleaner, cleaned the throttle body which had alot of black build up in the bottom to middle part. I've used water wetter and Lucas fuel treatment and its still doin the thing. It has a Roto Fab CIA and the stock GM dual performance exhaust. No tune or any other mods. My friend that used to work as a tech for chevy scanned it and it wasn't throwing any misfire codes or any other code for that matter but he said if its a valve issue it wouldn't necessarily throw a code. I've read that the engine for the manual tranny does use the active fuel management system so hopefully its not a valve issue. He's going to contact the local chevy place he worked at so when I bring it in they'll put an experienced tech on it. Any ideas on what it could be? Is the idle on these cars naturally alittle rough?

[ctrlz]

Assuming no modifications, there should not be a rough idle. Maybe check fuel trims to rule out vacuum leak.
You might get a few misfires on a cold engine, but not enough to set a CEL. Once warmed up, this should not be an issue.
AFM is not activated on manual transmission cars.

[Donjazz]

It almost feels like a ghost cam tune. Which I don't know if the previous owner tune it or not. Its not terrible but you can feel it sitting in your seat. The idle rpm stays steady at 600rpm but it feels like the exhaust shaking or rumbling from time to time slightly. Its hard to describe. My friend reset the fuel trims and it still does it.