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.

 

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...

 

It leans it out but not to dangerous levels.

 

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

 

my a/f looks fine to me

 

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

 

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

 

Service engine soon light came on again today...

 

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

 

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

 

Dynoed mine and it was fine 13.2 +/-

Nismo with berk metalic HFC



>

 

yeah mine was above 13 as well on the dyno.

 

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

 

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..