Hi everyone
this is driving me insane. I just changed the fuel filter on my 300E after my hunch that it was the original one (1987) and full of sediment was bang on. But no sooner can i congratulate myself, i have discovered that now the car drives rough, like it's missing on one pot. I have noticed it starts better though.

can anyone advise? Is this normal? By the way, it does not have an o2 sensor fitted as the previous owner changed the exhaust at some point and opted for one which didn't have the plug (i guess a cheaper system)

Any advice would be greatly appreciated

martin in beirut