Posted about this the other day, but have a follow up with some extra information now that I’ve had the chance to look at it more.

Replaced the valve gasket cover a week ago. Prior to that, everything was fine aside from my oil leak.

After replacing it, the following is occurring:

-Weird idle. Sounds like a mix between a Harley and a tractor. Has a “heartbeat” that surges through the vehicle and is felt. More noticeable after driving and then coming to a stop and idle. Also occurs when driving at times, which causes the vehicle to “stutter” and shake.

-Exhaust from tail pipe thicker/heavier in volume more than normal. Not visible when driving, but visible when stopped. Leaving black soot on liftgate, but exhaust can appear more white at times and black at others.

-Exhaust leaking from somewhere at back of engine bay behind or to the drivers side of the valve cover. Visible similar to from exhaust pipe, and smell coming into the vehicle.

I’m assuming the above are all related to whatever the cause is. A few things of note:

-I replaced the vacuum kit for the front since I had messed up the main hose off the front of the valve cover. Didn’t solve the issue.

-Nothing else was done during the valve gasket cover replace, but did get a little rough on the back side of the cover trying to reach some bolts. Possible I disconnected something on accident?

Any help or thoughts would be very much appreciated! I’m really new to fixing my own car, but am trying to learn! Thanks!