See post #29 in the "GOOD INDY SHOPS NATIONWIDE". I just bumped it to the top.

Just wanted to post a quick update. After doing more diagnostic we discovered that it is running on lean mixture. So, I will update the details as soon as we get to the bottom of the issue and fix it. Talk to you soon.

There's a DIY for verifying fuel pump/pressure regulator function. All you need is a $20 fuel rail pressure test gauge from Harbor Freight.

Need it bumped to top?

You have an I6, check the Disa Valve. Two torx screws and one electrical connector is all it take to remove the Disa Valve. When you remove the Disa valve, note the effort it takes to pull it out from the intake manifold. There should be some resistance. If it comes out easily, the seal is no good. You can buy a new Disa valve or you can use an o-ring to replace the old seal. Also check the flap and make sure the pin that secure the flap is still there.

You can find out a lot about the Disa valve by going to the Youtube channel and doing a search.

During the process checking DISA valve I discovered a tear in the hose that is located below the DISA.
I just wanted to confirm that it is lower intake boot, isn't it?
Interesting how it was not noticed during mechanics inspection.

Yep that the lower intake manifold boot, also a common source for vacuum leaks.

Here's a link to another thread on the same issue.

http://www.xoutpost.com/956702-post2.html

Did this come on all of a sudden, had you noticed it for some period of time or did you first learn of the misfire when you did diagnostics?

Hi,
It began with esl indicated on the dash.
And the same time engine loosing power and misfiring. It was strange.
After completing diagnosis codes that I attached with the pictures I began my journey to trace the issue with all the sources
I should stop at nearest dealership to buy the part and replace it.
We'll see after that. I hope it would resolve the problem. I will keep you posted

Please keep us posted if replacing the intake boot resolve your problems. There are many X owners that comes on this forum asking for help, but most rarely post the solution to their problems once their problem is fixed so the thread is worthless for future owners with similar problems.