I have an 05 hemi with cat back exhaust and i didnt notice that much of a gain in HP and i was wondering what would happen if i removed the cats when i put new hedders on??? I know I would gain HP but would it F#$K anything up or just throw an error code... I used to have a 02 W/ a 4.7 and I cut the cat off and all it did was make my check engine light stay on... has any one done this yet and what has happened...some! told me it would fry my computer??? thanks for your input!!

 

You should not run open pipes you dont have enough power to do that you need at least 400 plus to run straight pipes, you will just lose power.

 

[quote]ORIGINAL: TANKZ400

You should not run open pipes you dont have enough power to do that you need at least 400 plus to run straight pipes, you will just lose power.
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+1 It will also be loud as hell.

 

ya dont take the cat out. itll mess up stuff

 

Cat removal will givea CEL and hurt performance unless you fool the PCM with non-foulers or do some other trick. Besides the Hemi comes with fairly high flowing cats anyway.
I put mine back on even after installing LT Headers, had to move them back about a foot and half, but they are still there.
A cat-back exhaust will give you a little more HP, but not really enough to feel. The cat-back real advantage is that it makes other breathing mods more efficient, and is just one piece of the puzzle along with a CAI and headers. That's where you should look to for more HP gains rather than removing the cats...

 

hammer would a 40 series hurt or help my truck? or would it change nothing from what i have?i just want it louder

 

every vehicle after 97 runs an 02 sensor before and after the cat. If you take it off or hollow it out your truck will run like ****. the other things are resonators and you can take them out

 

pm answered...