I just picked up a 2002 Ram 1500 with a K&N breather and a freeflow exhaust. It is amazing while excelerating but runs rough between 1500 and 1600 rpm's. Unfortunately this is where the truck likes to cruise when in overdrive on the highway. As soon as I step on the gas I get a brief shudder until I pass above 1600. Any suggestions? Performance chip (what kind?)? Better gas? New plugs? :banghead:

If you manually shift to a lower gear and drive so the RPM is at about 1600, does the engine still run rough?
Without actually driving it myself it would be hard to diagnose, are you sure the shutter isn't being caused by the Torque Converter clutch studdering? My Dad had that problem with his Dodge Truck so he traded it in. His got air into the fluid b/c the dealer (while changing fluid and filter) started the truck and tried to drive it without fluid in it. This can also be caused by putting a quart of the wrong fluid into it, these Transmissions require special fluid that you can usually only get at a Dodge Dealer.
On the other hand, it could be an engine problem, good luck!

Check engine light on?

I just picked up a 2002 Ram 1500 with a K&N breather and a freeflow exhaust. It is amazing while excelerating but runs rough between 1500 and 1600 rpm's. Unfortunately this is where the truck likes to cruise when in overdrive on the highway. As soon as I step on the gas I get a brief shudder until I pass above 1600. Any suggestions? Performance chip (what kind?)? Better gas? New plugs? :banghead:

I think the first thing I would do is to have the tranny flushed, fluid and filter changed. This would ensure the correct fluid is installed also. As mentioned above these are very picky about the fluid they run with. Here's some generic info on tranny operation. Might have a dead spot in the TPS on the throttle body?

OPERATION
The application of each driving or holding component is controlled by the valve body based upon the manual lever position, throttle pressure, and governor pressure. The governor pressure is a variable pressure input to the valve body and is one of the signals that a shift is necessary. First through fourth gear are obtained by selectively applying and releasing the different clutches and bands. Engine power is thereby routed to the various planetary gear assemblies which combine with the overrunning clutch assemblies to generate the different gear ratios. The torque converter clutch is hydraulically applied and is released when fluid is vented from the hydraulic circuit by the Torque Converter Control (TCC) solenoid on the valve body. The torque converter clutch is controlled by the Powertrain Control Module (PCM) . The torque converter clutch engages in fourth gear, and in third gear under various conditions, such as when the O/D switch is OFF, when the vehicle is cruising on a level surface after the vehicle has warmed up. The torque converter clutch will disengage momentarily when an increase in engine load is sensed by the PCM, such as when the vehicle begins to go uphill or the throttle pressure is increased. The torque converter clutch feature increases fuel economy and reduces the transmission fluid temperature.
Since the overdrive clutch is applied in fourth gear only and the direct clutch is applied in all ranges except fourth gear, the transmission operation for park, neutral, and first through third gear will be described first. Once these powerflows are described, the third to fourth shift sequence will be described.

OK,

So let me get this straight. This is a transmission problem, not an engine problem? I am confused but willing to listen. I have already tried better gas, engine cleaner, and cleaning the air cleaner. If you guys say it might be the tranny then I'm willing to give it a shot. Just so we're clear...here is a little more info.

This happens between 1500 and 1600rpm's when there is little if any load being put on the engine. When I do so gradually, it shudders, and jerks like it is starving for fuel. It could be the tranny masking like this I guess. If I disengage the O/D it does it less often because the revs are kept higher, but it will still do it if I let the revs fall below 1500rpms. When it occurs, it does not change into a lower gear as it would during hard exceleration.

This AM I paid real attention to it and the thing that troubles me is that it seems to happen intermittantly, I can't get it to do it all the time. It definitely doesn't occur if any uphill load is being put on the engine. It also doesn't seem to occur going downhill...again, back-pressure on the engine and pressure on the gearing may be keeping it from happening. Weird.

Stevo2 -What is a TPS?

TPS is the Throttle Position Sensor.
It is similar to a volume control , but for the throttle. It tells the computer what the position of the throttle is. If you have ever adjusted the volume on an old radio and there was a scratchy sound when you turned the knob or there was a spot in the control where there was no volume or max volume. You will get the idea of what could be wrong if the TPS is getting "scratchy". The computer could be getting bad signals from the TPS but not all of the time.

What's freeflow exhaust anyways?