I used propane and a tube to shoot gas around the base the best I could while the car was idling. No change in rpms. Not a full proof method. I am probably going to need a smoke test done to be sure.I've seen threads on intake manifold cracks at this forum. Some get them seriously cracked to the point of getting CELs, but some say they got mild symptoms long before things got worse.
Is there a way to know if your IM is sucking some air?
I might be paranoid, but I think mine might have some mild air leak. And this would explain fuel beeing too lean and detonation.
The dealership did pull the intake manifold a year back to check the runners due to the tick. They ended up replacing timing chain tensioners . I wouldn't be surprised it didnt go back on right... maybe pinched gasket or like you said small crack.
I am wanting to try everything before taking kit off. If I take it off and everything is fine, I will not put it back on.