Vehicle Complaint- SHAKING motor
Vehicle- 2001 Ford F-150 5.4 2v (Lariat)
Mods- Completely Stock
Miles- 175,000
Recent Maintenance (6moths)- Drivers Exhaust Manifold and Head Gasket Replace. Timing components replaced and removed small plastic from oil pan. Rear outer bearing and Diff clutch packs replaced.

I recently noticed a little white smoke coming off tailpipe, and noticed my coolant was a little low... I was worried that the head gasket was leaking again, so I did a radiator pressure test and found the intake leaking the rear driver side. I have fixed that issue by tightening the rear bolt (pressure test okay now).

The truck is SHAKING.. I have no DTCs or CEL, but have some I/M codes for EGR, HTR, CAT, O2S

The truck seems to do okay when in open loop, but quickly starts the shake at idle. The truck will not die, and the RPMS do not fluctuate. When I put the truck in gear, the shaking gets worse when I add throttle (reverse also). The trans fluid is good. The truck doesn't drive smooth either, but if I increase my RPM's around 2500 in park the engine seems to stop shaking. EGR Valve opens and closes well. MAF and IAT tests good. I tried to get temps before and after cats but can't get a good reading on the ground.

LTFT B1 is about 20% at IDLE with STFT -5% - 0.
LTFT B2 is 0 with STFT ~0
The upstream O2 sensors are reactive and "appear" to be working properly fluctuating between .01 and .9.
The downstream O2 sensor is rich bank 1 .700 fluctuating slightly
The downstream 02 sensor is lean bank 2 .300 fluctuating slightly

With the high LTFT, I would assume I have a vacuum leak, but intake manifold vacuum is at 20hg at idle and drops to 0 on WOT.
I guess I need to pull all the plugs and test the injectors? I would greatly appreciate some assistance narrowing this down.

Thanks for your time.

 

Replace the intake manifold gaskets
Check the plastic intake manifold for the lower plenum being loose, warped or cracked.