The engine does not have enought power in low RPM

Running rough is describing a misfire condition, so low power can be expected. How long since the engine was tuned up or the spark plugs were replaced?

I put in new spark plugs and new cap and new air filter.
Also i put in one fuel cleaner in the gas.
The diagnostic connection is ded .

Fuel system cleaners are just a highly-concentrated version of the additives already found in gas. Those chemicals will not solve a misfire.

You might get a clue as to where to start looking by reading and recording the diagnostic fault codes. Do you know how to do that yourself?

Hi MIRCEALELE

here is a link to great information on scanning for codes. The link contains an article that features written step by step instructions and pictures explaining how to do the scan yourself. Also, I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the codes please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin

If the diagnostic port has no power, check fuse 12. It powers pin 16 in the connector. Pin 5 in the connector is ground, it runs out to a connection on the front of the engine. If either is missing most scan tools won't operate.