downpipes

Hello i have a question, i recently picked up a 2.5 inch Downpipe on my Seat Leon 2007 2.0tdi 170hp but i have a 2.3 catback will this cause flow problems or am i good?

i've been on phone to powerflow and they recommended demon tweeks demon tweeks have never made one and id be first :| so theyd make it, fit it and then price me (no thanks) blueflame never reply or answer the phone! miltek are very expensive.. I currently have a cat back made...

I've spotted 2 different types of downpipe and de-cat systems going on ebay and was wondering if anyone has bought these and if they are any good? Having 2 lambda sensors a guess the 2nd one would be a better option.... unless they are both a pile of doo-doo.....? Also, anyone know of...

where do i get a bigger downpipe for a ibiza cupra? Not really looking at replacing the cat unless i can help it, any prices/pictures etc guys? Thanks also what size you recommend? i want to keep std backbox etc if poss too

Hi all, looking for a new downpipe for my ibiza. Looking at a&m or milltek I think, any suggestions on either or peoples preference. a&m is 3'' and milltek 2.5'' does it make much difference, and i believe both are 100cel cats. Thinking about k03s soon too, so would one suit the k03s better that...