peugeot 206,2003, engine diagnosis (engine block) light is on constantly.judders and slows dramatically going uphill and sometimes on the flat..loss of rev's&power.rich fuel smell. few garages have looked at it. 1 mentioned the coil; another said the catalitic converter had melted or blocked(tried to fit new one)one answer mentioned spark plugs!could this be the problem??help!!

Sounds like it!!!!!!!!!!!!!!!!!!!!!!!!!1

Thus begins a never ending battle to make another Peugeot run. Dude, they ALL run like that and NO ONE can really fix them.

If the catalytic converter is blocked, this prevents all exhaust gases from escaping, & u will have NO power. Your car might run normally for 3 minutes when u first start it up, before the exhaust pressure builds.
What do u mean ''tried to fit a new one''? Were u successful?

Changing the 4 spark plugs is a low cost trial. However, they must be pretty fouled to give u this serious loss of problems. You will know as soon as u look at them. Oily & wet? That is too rich a mixutre & u can smell that sometimes.

Coil melted? car is only 3 years old? l doubt it. You would have NO spark & no driving at all.

How is ur clutch? A warn out clutch plate would give u NO POWER, juddering, no acceleration, no power on hills, & u would smell the clutch lining getting hot from too much slipping.

Engine light constantly on? Hmmm. l am only guessing the oil pressure is low, or something is always hot, it is a guess?
All Peugeots can be fixed. ALL. Just not by an American armchair ''expert''. Those who cannot help on this website, just get two points for insults.