Need some quick help

Gibby1113

If I wanna install some HFCs that do not have the extended O2 bung will I get a CEL? I'm interested in getting the ark HFCs and they don't come with the curved part to connect the O2 sensor. Is there anything I can do to make sure a CEL doesn't go off w/out having to tune my car? I know these are pretty stupid questions but I wanna make sure my car isn't gonna mess up after I spend money fixing it up.

My Z is my DD and right now I'm getting 18.8-19 mpg and I currently have the takeda cai and ark dts exhaust. Will adding HFCs make my mpg worse or will it hardly affect it?

One last question for now. When I installed the ark dts exhaust I felt my car a little heavier on the back end and the response of the car was about the same. Will adding the HFCs make my car more responsive or will it do nothing at all? Thanks for the advice in advance!

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40th anniversary #450/1000 | Takeda Attack CAI | Ark DTS exhaust | to be continued...