I don't think it's any drag on the motor from the serp belt. It would squeal with that much drag and it's too consistent with how it runs. Also that wouldn't explain when it starts running crappy when it tries to drop to an idle and dies.

Already ran it with an open header. Not a plugged cat.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

did you ever find the problem im having the same issue

Which part? The truck has no power and sounds like it's burping? If so it's the cat.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

so a new cat fixed your problem? i removed my cat and my truck still ran like crap. its bogging down and doesnt want to accelerate without wanting to die. even dies when i turn the a/c on. im starting to think i have a bad ground

Yeah if you removed the cat and it still ran bad it's not that. Check wiring and plugs. Is it missfiring? Do you have a vacuum leak? What have you tried so far?

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

iv checked fuel pressure its fine but with the truck in the off position the fuel pressure drops super fast i dont think that would cause my truck to run like that. ive tried a new iac,tps,computer,maf,new spark plugs and wires, timing is dead on, tried reading for codes but theres nothing.

Gotta check the fuel and vacuum while it's running bad. The vacuum will tell you a lot about what's going on.

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Also check compression with the engine warmed up.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

video of how my truck is running

as you can see when i give it throttlle its hesitates bad.

ive done a compression test all cylinders 150+

Doesn't sound like a clogged exhaust really... Um I'd check vacuum and maybe swap coils see if that changes anything. Almost looks like the tps isn't working or something. Check the fuel filter too.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

ok i think i might have found my problem
so i went ahead and re checked my timing
i lined up the cam and oil sprockets to there triangle/diamond
but my crank pulley line is behind BTC!!!
shouldnt it be at TC?

IM SURE MY TIMING IS OFF

Yeah sounds like the timing is off. Reset and try again.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done

Yeah so get the motor at TDC with no belt on. Then line the cam and oil pump up.

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99 extended cab, 4.0, auto, 33s, 4x4 lifted with some stuff done

98 2wd 2.5, 5 speed, dropped with some stuff done