Hi,

Well after I got my wheels I said no more mods but I saw the nice gains from Crawford HFC's so I plan on getting them. A couple q's though:

1. Does anyone have a pdf of the HFC installation guide - I want to make sure the install is easy and won't mess up my car

2. Crawford site says:
with bungs installed for use with the factory oxygen sensors

Does that mean the bungs will help the cats to NOT throw a CEL light?

Cheers ,
Clint

no bungs means that they have a place to install the sensors, get a set of non foulers from a local auto parts store.

install is relatively easy. you'll want 30" worth of extensions, though.

the cats should not throw a CEL.

HF cats should not throw a CEL, most of the time test pipes will but not HF cats. Mine never did when I had them.

Had a little trouble finding dyno sheets with before and after numbers using the Crawford Cats. What kind of gains should be expected with this mod? (Sorry clinthammer, not trying to jack your thread!)

5-10whp I think.

btw since i already have the MD 5/16 plenum spacer, is it even worth putting on the Crawford Polished Upper Plenum or should I spend that $500 on something else?

Cheers.

i had a 5/16 spacer and swapped it for the crawford. noticed a little diff mostly high end, but not much. i have been looking into hfc's and headers as well

I have FI HFCs- they are much smaller than the Crawfords and they sound awesome

however, I get a SES light everytime it rains.. ..I dun know why