gambino

Hey guys. I was told from a very reliable source that test pipes lean out the fuel to a dangerous level and HFC's also cause it to be lean, just not as bad as test pipes. I trust this source, I just want everyone elses thoughts and opinions.

nareg

iTrader: (1)

my car leaned out quite a bit with the test pipes but it was still i think 12.9 afr on motor and 11.5 or somthing like that on spray so its not too bad...

App6MT

iTrader: (1)

It leans it out but not to dangerous levels.

Datona Jess

iTrader: (1)

I agree it leans it out.
I have seen it on other engines my buddy's 06 anyway.
It is not dangerous though, the factory tune is a bit rich so you are good to go. I have some on my 08 and she is running GREAT

Gooey

iTrader: (18)

my a/f looks fine to me

mcarlomagno

i think my car runs a little rich anyway. so i'm sure moving toward the lean side couldn't hurt.

THE_SCHROED

iTrader: (21)

Mine throws a code every now and then saying it's running too lean. I doubt it is really gonna hurt it though.

THE_SCHROED

iTrader: (21)

Service engine soon light came on again today...

gambino

hmmm, interesting. And I guess combining this with an intake will do nothing but make it run slightly leaner...

sbZenth

iTrader: (23)

yeah my a/f is fine too. itll throw the CEL every once in a while but thats about it...

WalkerT

iTrader: (13)

Dynoed mine and it was fine 13.2 +/-

Nismo with berk metalic HFC



>

sbZenth

iTrader: (23)

yeah mine was above 13 as well on the dyno.

davidv

iTrader: (2)

One good thing about this forum is that you can get any answer that you want.

Asian Invasian

iTrader: (31)

It really is going to depend on your car. I thought mine ws running lean but ended up being about 12.77 with the mods in my signature. You are going to be fine imo.. but like I said it depends on your Z..