what diagnostic scanner are you using if I may ask.
I have a XTOOL D7, it has the crossfire model. It scans then at the very end says it can't communicate with the ECU 😡

 

Mine was doing the same thing. I pulled my coils off. Everyone was cracked on the back. Replaced them and plugs and wires. Not done it since.

 

There is a vaccum port on the front underside of the intake manifold. You cannot see it. But you can get a few fingers on it. With the car running try to gently wiggle it and see if anything changes. If not spray some carb clean on it. If the idle changes, then that rubber piece that comes through the manifold is dry rotted. If it is rotten, There are a few options. You can push a small brass tube inside of it and then reconnect your vacuum line. Mine was so bad that it fell apart when I touched it. I either had to buy another manifold or fix it. Evidently that piece is not sold seperate from the intake. I pulled my manifold and split it open, then made a new piece. That job sucks. It takes 2 people to adhere it back together properly.

 

Hi Machfivexf,
You wouldn't happen to have any pictures of the vacuum port repair you performed. Is it on the passenger or drivers side of the intake manifold?
Thanks,
-Jerry

 

I do. But cannot access those at current. Waiting on a new battery for my laptop. On the NA. It is just behind the air pump. On the bottom of the manifold pretty much in the middle. After the air pump has been removed you van follow the only vacuum line that goes there. You cannot see it and barely get a finger on it. A quick test before you remove the air pump is while it is running. If it will idle. Use the tube that comes on a can of carb clean and spray in that location. See if anything changes in the idle. It attaches to the hose that my finger os touching. I believe it controls the flappers inside of the intake.

 

I found my pics of when I split the indians.

Rotten vacuum hose at lower intake

This is inside of the intake where the hose plugs in

It was also not tite where it plugged in.

Combination of hoses and a brass tube. I was testing the fit for tightness. Adapter was installed on the short end of the bend after a test fit.

When installing. I had to insert just the hoses. And they should be very hard to get into the hole. Then I inserted the brass tube using lube. I inserted the brass tube past the hole as it made the vacuum hoses tight enough to seal. Also leaving enough inside for the control to make a tight seal.

I used mercedes sealant to seal the two pieces of the intake. And also coated the outside for extra protection and in case my fix was not tight enough. I let the sealant set up for 24 hours before reinstalling the complete intake. It is still holding just fine. This was in 2021.

Another thing is the factory piece was also rotten and cracked on the inside of the intake. It had a vacuum leak inside of the intake at the same time.

This is probably not your problem. However it caused most of the symptoms that you have been describing.

 

Also found these emission tubes almost clogged completely.

 

Hi Machfivexf
Great Pic's, thanks for posting. Just another thing I have to check.
-Jerry