HI, I have a 97 F150 4.6L and I currently have a flowmaster cat back exhaust (2 1/4", single in-dual out). It sounds great, but power increase is only psychological. I'm planning on supercharging and I think that a true dual exhaust system will help with my needs. I was wondering if any one had any problems with true dual exhaust modifications (after the cats)? I'm concerned if the exhaust gases may escape to fast for the O2 sensors to read. I appreciate your time.

 

I have a 01' 5.4 with true dual exhaust (40 series/2 chamber flowmaster, 2.25 inch pipe, and the back two cats removed). Also now have a set of bassani shorty headers. As of now i have had no problems with any check engine lights coming on. Truck runs with no problems like the day i bought it.....just with a bit more power now.

justin

 

just_right

How big of a difference in sound did it make when you removed the back 2 cats on your pickup? We are talking of doing this to my '99 Right now and was wondering if it made any difference.

Thanks

 

tobyk,

I've got duals on my truck, sort of.

I cut out the factory Y-pipe and installed a Magnaflow X-pipe. Then I ran two 2.5 " pipes into a Magnaflow DI/DO muffler.

No problems yet. Sound it great, and the truck will jump off the line.

 

Properly sized "true" duals will not negatively affect your O2 sensor readings or trip the CE light.

 

I already had true dual with the flowmaster up until about 3 weeks ago. Then i added a set of bassani shorty headers..... no real noticable difference in loudness with the addition (just a slightly different tone maybe). About three days later i went to the muffler shop and had him remove the back two cats. I can deffinitely say its louder now while sitting still and driving at highway speeds. BUT (dealing with highway speeds)i have my exhaust run out in front of the passenger side tire so i know that is the big reason for being louder in the cab at upper speeds. When i say its louder, i dont' mean its unbearable. Before you could tell the exhaust was there but wasnt' quite as loud as i wanted. I have also let somebody drive it with me beside the road and it sounds great. It reminds me of a lightning with bassani exhaust....minus the sc But i would definitely say its gonna be atleast half again as loud as it is now...maybe a little more. I don't like anything being tooooo loud so this is about what i like. I dont' think i would remove all 4 cats though now that i have heard it with just 2 removed. That would have to be too loud. Sorry for the long post.

justin

 

Yeah I was at my exhaust shop back at home over spring break and we talked about removing the back 2 cats. I am running straight pipes so it should be noticeably louder. Well at least that is what I am hoping.

I like my exahaust to have a nice crisp snapping sound to it, many have compared my pipes to a vintage muscle car. I'm just going for some more sound.

thanks

do you have any recordings of your pipes?

If you would like to hear mine drop me an e-mail

stangs69@hotmail.com

 

Thanks for all of the info. I feel confident about installing the true dual exhaust now. Also, I was thinking about changing to Borla mufflers. Even though they are a lot more expensive than Flowmaster, I think it has a little more "richer" tone. Thank you

 

Awesome!!! Someone who has finally done it. I am considering having my pre-cats removed. How did you "fool" your rear O2 sensors if at all? How did it effect the truck?

-AR

 

With the removal two of the cats i was wondering if the check engine light would come on....and especially since i installed headers too, but nothing so far and it has been a few weeks now. I didn't remove the two front cats, i removed the two closest to the back of the truck.....seems easier to remove the two rear ones. If the check engine light had come on i was going to order a pair of MIL Eliminators but i didn't even have to do that. If you are wanting to know what the headers and cat removal do for performance i'll be running it at the track tonight. I went last weekend but all i did was spin. But i'll have to get back with ya on that.

justin