loud fuel pump and shuddering while driving

[95k1500z71]

So my truck is a 1997 350 vortec el60e z71. and while im driving down the road and the truck gets to cursing speed. the truck will start to shudder. when you step down on the throttle is goes away. also the fuel pump is extremely loud. would y'all say the the fuel pressure is dropping off and its starving for fuel?
Truck also has code P0430 Catalyst system efficiency below threshold bank 2. so im guessing possible bad cat?

 

[95k1500z71]

No one?

 

[GL1500]

Never had a pump go bad but it seems if it were losing pressure the shudder would remain or get worse when you step on the gas. I would suspect the TPS but that's just a stab in the dark based on your description. Pretty easy to test.

 

[sntrym]

I would fix the code first before you troubleshoot anything else. The O2 sensor on bank 2 is either bad or the cat is clogged. This could be causing the shudder.

The shudder could also be the torque converter. I doubt it's the fuel pump since when you step on the gas it goes. If the fuel pump was a problem, the shudder would happen when you stepped on the gas.

 

[lamogo33]

Sounds like a plugged cat.

 

[95k1500z71]

Okay thanks for the replies. Cats dont normally make it to long on my trucks but i just got this one and havent had time to get the exhaust work yet. It sounds terrible lol. I have searched and i dont see much on what people do with the O2 sensors once the cat is gone. All my my Chevys and GMCs where pre votvec so i only had one and it was before the cat. Is Black Bear tune the best for that?

 

[95k1500z71]

Well i cut the cats off and the pass. side cat you could barely see a little light coming though it driver side one not much better. But the truck runs better but the shudder i actually think is a back fire it still there. And it only happens when you pressing lightly on the throttle. The truck right after i bought it coded for misfire on number 4 and had a miss in it. I put new plugs, wires, cap and button on. And it went away. Anyone have any ideas on what direction to point me in now. lol

 

[95k1500z71]

Now I'm getting a p0300 code?

 

[95k1500z71]

truck is still backfiring after a new fuel pump. Does anyone have any ideas. Could it be the ICM or a MAF sensor?

 

[Thatfordguy]

Did you ever do anything with your 02 sensors after you chopped the cats out? If not either get them tuned out or make some mini cats. Just search mini cats on here and you'll find what you need. If those sensors aren't reading it will cause the truck to run like ****