Awafrican
Moderator
what test pipe do you have? my vote for DP is ATP https://edgeautosport.com/atp-turbo-upper-downpipe-3-mazdaspeed-3-2007-2013/ I hear the CS one is decent with the divorce tube as wellyep cancelled https://news.ontario.ca/opo/en/2018...outdated-ineffective-drive-clean-program.html and good riddance.
All the POS rust buckets i have owned in the paste never failed the etest, clear it was money grab
So now I'm on the hunt for down pipe to go with my test pipe i need to install.