try to have good exhaust sound but loose to much back pressure

:smile: i have replaced my stock muffler with a turbo free flow muffler and my cat has being removed and replaced it with a 19 inch 2.25 resinator but finding it difficult to tune idle even after following manufacturs service procedure ? also find it rich in fuel smell out exhaust and cold running find it jerky and erratic has any body got any idea on how to over come problem or a good suggestion to improve performance but keep nice sound as in new zealand you cant buy of the shelf performance muffler system which suxs