no power on 1995 BMW 318ti

i changed the plugs and lost all kind of power idle a lil rough but not to bad cant get over 50mph no power goin up hill or startin off did everythin to my knowlegde cant figure it out

Asked by for the 1995 BMW 318ti
Sounds like the problem I had with my 1998 318ti. Most likely your catalytic converter is clogged, BMW had a recall on the catalytic converters on the 318's they are known to go bad.