This question was asked by my brother in law and since i don't have an '05, can't really answer it for him. Hoping someone here could shed a lil' light.

......"Gotta question for you though. I got the whole thing installed at one
of the very last steps in the instructions tells me to remove the
"Hydrocarbon trap" from the factory intake hose, if my car came with a
hydrocarbon trap, which apparently it doesn't because there wasn't one in
my intake hose. Then, you're suppose to take that factory hydrocarbon trap
and install it into the K&N intake. Since I didn't have one in the factory
intake, I assume I don't need it in the K&N intake but there's a blurb in
the following set of instructions that says, "This intake system is
designed to use the factory Hydrocarbon trap. Failure to use it will
result in poor performance or possible engine damage".
So now I'm scared! Do I need that Hydrocarbon piece or don't I???

Anyone here care to take a stab at this one ??

 

Per K&N you do not need to put the hydrocarbon trap in if you don't have one. It will not cause engine damage or poor performance.

 

The 05 Mustang on Horsepower tv the other day had a hydrocarbon trap,and it showed them put it into the K&N intake.

 

So, not all 'stangs came with the hydrocarbon trap? Whats the deal with that? BTW, this car was purchased in Virginia.

 

From my understanding, Ford stopped putting them int he mustangs about 1/3 way through production ( not sure though). I have mine cause I took it out. If you want it, PM me and I can send it to you. It is super clean, and looks brand new.

 

Thanks, PM sent.

 

for those interested I put a post in GT tech and performance for my findings on the HC trap. Here is my post
well today I finally got my stang dynoed with MTAS. I have the K&N aircharger of which I did place my HC trap back in as per the instructions and got a base pull on my stang.
Mustang Dyno
With the HC trap in
246 @ 5850 HP
250 @ 4500 torque
and that is with a Predator 87 tune
I was kinda hoping for a bit more but she is what she is.
now I asked the tuner to do a pull without the HC trap
242@ 5250 HP
249 @ 4650 torque
now you have to take in the fact that the computer was still learning the fact that I took out my HC trap and the tuner said I may end up with a bit more HP than that.
Now for the VERY unanswered question of how it runs without the HC trap. The Air Fuel ratio had very little effect and was told that it would not harm the engine to remove the HC trap. The only thing I did notice is that after the Dyno I had a 2 hour drive home to kinda test things out and one thing that stood out was that when ever I went WOT my car pinged considerably 2 times on the way home. NOW to my knowledge my car never did this before so for right now I am going to leave my HC trap out a few more days and keep an eye on it.
So I hope this answers some questions. One I wish that Diablo would finally put a tune out for the K&N and Two it looks like I have to look into a few more options to get my car to the 300 rwhp mark I am aiming for.

 

The Hydrocarbon Trap is created to trap carbons from being released into the air when you shut your car off. The only thing it does while your car is running is creating one more thing the air has to pass through before getting to your engine. It doesn't filter anything it just blocks air passage which in turn gives you worse gas mileage and a touch less hp. This is probably why Ford isn't putting them in anymore, because everyone is catching on to their uselessness. I recommend yanking it, it's very liberating.

 

I noticed the base run w/ the trap in, says you had 246hp at 5850rpm, but the trap out run, the 242hp came at a lower 5250rpm. With only a difference of 4 hp, wouldn't the 600rpm difference make up for that, as the hp curve would still be increasing past the 5250rpm mark in the no trap run?!? :scratch:

Did your HP really peak at just 5250rpm on the no trap run?

 

HP peak at 5250 is really low, wonder if it went super lean and couldnt make any more power.

EDIT i just notice you said it was pinging, thats definately a sign of it running lean.

 

HP peak at 5250 is where the torque/HP curves cross. You're running way too lean, and/or your torque curve drops off dramatically.

 

The pinging has stopped. I'm going to upgrade my octane today to 93 and do a predator tune accordingly.
with the HC trap in my air fuel ratio was
between 12.03 to 14.26

and with the HC trap out.
12.28 to 13.10

 

Took mine out last night after reading this topic.

 

Let us know how it runs since taking it out. I'm curious.