Ill be honest with you.. Ive read alot that you loose low end torque when you daul out if you do not do some major mods in the engine to support it.. its just like taking the breather right off and letting it bog with too much air if the fuel cant keep up..

Same thing applies in the exhaust.. there has to be certain amounts of back pressure to keep the engine running like it should..

 

Well I've got a flowmaster exhaust. Single inlet and dual outlet. I'm running just 2 1/4 inch pipe from exhaust out so I'm still keeping some back pressure in since I'm not running large piping. I know our trucks need to keep that back pressure in there. In time and money I plan on dong more mods to it but with a tighter budget and replacing parts on it on a regular im almost at a standstill plus I'm not too sure what mods to really do next

 

Yeah I'm right there with you.. most of the mods do really little for you.. unless you combine them with other mods.. then overall each together creating a difference. Some of the mods really in my opinion are not really worth the little bit of gain you get.. My truck is 4x4, its ment for off roading.. thats what I bought it for.. I would like a better response curve but at what cost?

I'm looking at my options.. Think i will just try and figure out this crap going on with it and then put some decent AT tires on the truck and call it a day..

 

same here. i would like decent mpg out of it but its a truck so im not gonna complain. eventually i'll get either a set of 32's or 33's and crank the torsion bars up front and through and extra leaf on the back and thats it right there. maybe if the engine blows on me one day i'll do some sort of a swap and go from there. that 3.9L is just too weak for the size of the truck ya know?

 

well bringing this thread back...just stopped at the shop and had them put on the cat and the o2 sensor....truck definetly runs a lot better now...no more sputtering or grumbling and seems to have a bit more power too. the sound is awesome also...idling is a bit louder/lower and when on the throttle, even just slightly, its got a deep roar to it. definitley worth it. now time to pay 3.50 a gallon and fill up on gas and see how the mpg is now.

 

So If you don't mind..

Orginally.. when you idicated a slight jerkyness when stopping.. Could you take your foot off the break from a stop and press no gas and kinda get a jerky feeling.. loping.. shuttering? Same could be said once you get close to being stopped?

Have/Can you recheck by doing this and see if you still have it or not..

Did you have a rough idle? Almost like a brum brum brum brum like it had a slight miss, out of timing.. or had a high performance cam kinda feeling?

Makes me wonder if it was the O2 Sensor or if it was just the CAT...
I put in new plugs on my truck and now seem a bit more powerful.. though I had new plugs before they were the non resistor type.. so I put OE style in and seems to be a little better.. but still has the shutter at almost dead stop (Creeping with no gas being pressed I'd say between 0-2mph..

Look like a plenum problem on the Intake Kegger..

But just curious.. Whats the model of Cat and O2 Sensor you put on..

Thanks.

 

the lope i had was i think more or less just the tranny shifting from 2nd to 1st when going from like 10-3 mph...but letting off the gas it just does that normal creep up on speed like every car does. idle seems fine...kinda revs a 100 rpms up and down here and there but nothing out of the ordinary. but the cat is magnaflow and just the ngk o2 sensor. im gonna see how it does tommorow morning when it starts up and is really cold out. usually it started and idled rough and was really loud

 

Yeah.. if it was lopping/shuttering like some of us is.. on current threads.. you would feel it creeping right around almost stopped.. it would shake the truck.. like it was missing or something..

I do not think you were having the same problem as us.. Good job if your truck is running better.. or seems that way with the added HP/Torque from the Hi flow cat..

Shame you did not grab some before/after vids..

 

Stupid question.. did you ever have any codes?

 

if i can find my video on my old phone from about a month or two ago when i did the seafoaming i'll throw that up and take a new one with the new cat on it too. i can definitely feel it when im getting on the highway or just when its reving up...it has almost a whole new sound to it and actually changes pitches throughout the rpms. the guy that put it on said that there was just one little piece rattling around inside the old cat...hmm...good thing i replaced when i did haha. but as for codes, the only code i ever got was just for the o2 sensor...bank 1 sensor 1 which is just the precat sensor. let me know whatever you figure out with yours cause with these dakotas im sure its a matter of time before i see something close. but it almost sounds like some kind of idle sensor or some other sensor