I have spent a lot of time researching this issue for a while, but basically... I got AMS sekushi test pipes a couple of months ago and I love how they sound and my car does feel to wake up a little earlier in the rev range. BUT, they smell!! In all honesty, the smell doesn't really bother me but that it because I have gotten used to it. The concern is with cops smelling me then deciding to pull me over or when getting smogged (I currently would have to go on a windy day so they wouldnt smell it). My question is this...

[1] Will a tune virtually eliminate the smell by itself and so i should continue getting the mods i want then get it tuned before registration comes up in a few months?

[2] Is the only way to actually eradicate the smell by getting a catalytic converter in the exhaust like with a catted y-pipe (looking at the AMS sekushi y-pipe because i loved the test pipes and they're on sale rn)?

[3] Would checking the current a/f ratio give me the answer i am looking for, and if so, which of the current vehicle sensors would i be looking at because i can access the raw data from almost all of the sensors for my car with the autel odb2 plug-in?

 

A tune won't reduce/eliminate the smell... At idle with a tune, or without, the AFR is around 14.7:1.
The only was to get rid of the smell is a high flow or OEM cat.

 

You need catalyst in your exhaust stream to counter the hydrogen sulfide. A tune is not going to change that chemistry.

It begs the question what cars smelled like before cats were a thing in the mid 70's. Pretty bad, I'm guessing.

Here's the wiki on cats: http://en.wikipedia.org/wiki/Catalytic_converter