so far i have replaced the O2 sensor before the cat, swapped out the Front and back sensor on intake, clamped the fat hose to the brake booster

still runs rough brake lights on dimly.. when you press the brake just ever so much to get that switch to turn brake lights on normally.. truck shuts off and the Odometer Light goes black.
is it the computer doing that? and is the computer the one on the firewall passenger side 3 plugs? it looks like 3 screws hold it in was gonna try swapping it

 

You need to figure out the hissing sound first. That's a vacuum leak and if it's bad enough will cause the engine to stall.

 

well the hissing goes away as the enging warms up or so

i swapped out the computer no change

i took the Vacum line off at the engine.. so nothing would need suction..
i swaped the 2 intake sensors
i changed that first O2 sensor
i clamped the big hose to Booster
when i had the little vacumm hose on i tried felling felt nothing..

is there another vacumm hose?
and for the Hissing it only comes from behind the 2 Barrels where that Cone Shape sensor goes into.. put your hand over it to quiet the hissing i dont hear any other hissing anywhere else

where else are there vacum lines.. i took the one off the passanger side that connects to the cruise control and whatever else its connected to... and that clamp still on the brake booster..
but brake lights still on when truck running..

 

so i swapped out throttle position sensor no change

so instead of me trying to follow all the vacum lines
which spot on the truck can i just run a new hose to

which sensor causes the brake lights to come on as soon as the truck is running.. as brake lights are off when key is off or when it stalls
but turns on dim and when you press the brake just to get the lights to come on it shuts the truck off or slows it and makes the low fuel light dim makes the odometer go black

so ive changed all 3 sensors on the intake.
changed the computer
changed the first O2 sensor not the second

would the 2nd O2 sensor being causing the brake lights come on
as i havent changed that.. trying to save money if i dont need to change

is there another computer thats causing this or another sensor.. as cant be vacumm causing the brake lights to come on and cause the dash to dim can it? and which sensors so i can just run a new hose from engine to it..

 

i was able to get the code reader to work this time.. had to hold the connector.. cant get it to work with the laptop version

the scan tool showed senors reporting numbers but the only 2 that wasnt is
speed which is because not moving
and
LTFT B1% it was 0
should that be 0 or a number could that be causing the issues i having

 

could it be the BCM thats causing issues?

my hand held Innova scan tool can read if i hold the port

my HP Tunners scan tool for laptop can connect hit and miss but cant start logging..

could BCM cause me not able to connect properly or cause the engine to run funny.. do i need to change the O2 sensor the 2nd one..
the hand held doesnt give read outs for it..

and if i bypass the odb port which wires could i use on my laptop one id jumper the wires would it be just a 2 3 wires or all are needed

 

LTFT is long term fuel trim. 0 is ok, but, kinda surprising. Did you reset the pcm in recent memory?

You have some electrical issues going on there. Think I would start by check all your grounds. Especially the ones on the front of the motor by the power steering pump.

 

when i watched the video about changing the O2 sensor they said to clear the codes

so i cleared them...
how many grounds are there.. or least the ones that are causing this issue.. go figure eh.

 

There are like two or three fat wires that go up by the PS pump. There are a bunch more scattered around. It really sounds like something is backfeeding in to the electrical system, as the engine still dies when you step on the brake, even with the booster vacuum line crimped off. That's GOTTA be electrical.

 

ah ok ill take a look tommorow if its not raining supposed to rain tommorow and snow the rest of the week lol and truck outside always something..
and i wish was easier to trouble shoot .. i guess what i have isnt common issue

i was thinking maybe BCM ? swapped out everything else lol