HELLO,
I AM NEW TO THIS WEBSITE, AND I WAS WONDERING IF ANYONE HAD ANY INPUT ON THE PROBELM I AM HAVING WITH MY RIDE. I HAVE A 01' C240, AND MY CAR IS IDLING VERY ROUGH AND MY CHECK ENGINE LIGHT IS ON. I SCANNED MY CAR, AND THE CODE THAT CAME UP WAS P0173, WHICH MEANS FUEL TRIM (BANK 2), BUT I HAVE NO IDEA WHAT THIS MEANS. EVERYDAY MY CAR GETS WORSE AND WORSE, CAN SOMEONE PLEASE HELP ME OUT! I'LL TAKE ANY INPUT POSSIBLE, THANKS.

 

bad fuel injector.

make sure your sparkplug is new.

was there any fault that says which cylinder is bad?

 

Sleepwalker is correct, bad injector or injectors, , in need of new plugs.