Filled up with gas on my 2012 ultry was runing fine 20 miles later it acts like it is ony running on 1 cylinder. How can I check this out to see if it is bad gas problem? Barely made it home, this morning in the garage it smells like gas.

 

drain the tank and add fresh gas

 

Sounds like EITMS might have turned on. You might also want to check for a spark at each plug. Could be plug wires, plugs, pinhole in fuel line inside the tank, dirty IAC or any other number of things. I also read about the temp sensor wire breaking and causing a similar issue.

 

Check for codes?

 

Check gas cap to make sure it is venting, after running the engine take the gas cap off and if you hear a rush of air going into the gas tank means a bad gas cap. Check the simple things first.

 

If it happened after you filled it up, its prolly bad gas. Flush it all out and start with fresh gas, go from there.