EmC

If anyone has any advice it would be much appreciated. My lupo has caused me nothing but issues over the last year. Recently by refusing to start. When turning the key the dash lights flash on and off and you can hear the engine attempting to start. Then nothing. Central locking keeps going on and off when doing this too. I've recently changed the battery, alternator, starter motor and spark plugs all to no avail. I got it working for 2 weeks and now its dead again. Read the codes and its just coming up with a catalyst system below threshold. Any ideas? Thanks guys.

When I start the car it revs fine, but as soon as you put any pressure on the throttle there is a clunking noise. All spark plugs have been changed, carb cleaned, oil changed, new air filter but still an issue with the knocking noise. Any ideas?

I have a set of BBS....I believe they are BBS ra433s. 14x6 4x100 et38. I have a 1.4 16v 2001 lupo sat on standard suspension. Any idea what size tyre would be best to go for?