Hi I have a 02 Rendezvous it runs but it has misfire when driving and a loud noise towards the top end under load. I'm not sure what it can be and I have a video of what it'* doing here. www.youtube.com/watch?v=GMquaYvgRUk

The only check engine lights are a misfire cylinder 5 and random misfire detected

The missing hose at the rear corner of the intake manifold connects from that port then a 90* elbow sends it toward the drivers side of the intake manifold where it connects onto the MAP sensor.....in your video you can see the clip that is holding the three spark plug wires together. The clip is resting on top of the letters "SFI". Well if you look at the other spark plug wire clip, that clip is resting on the MAP sensor.

Wait....I'm mistaken....sorry, I didn't notice the year you identified your vehicle as.....in any case. That port can be capped off as you have it now....but I think it is supposed to have a hose connected to it leading into the passenger compartment to supply vacuum for the a/c heater vent controls.

The other port at the other end of the intake manifold....there is supposed to connect onto the transmission.

The noise you hear could be "piston-slap". Does the sound go away after the engine is fully up to operating temperature?

Here is a link to a pic of that rearward vacuum port.....see how the hose comes off it and travels towards the passenger cabin of the car........different vehicle......same system.

http://troubleshootmyvehicle.com/gm/...crank-sensor-1

When it'* at idle it'* fine but when I drive it around it increases with the rpms and also it has a gas smell out of the exhaust

Have you addressed the cyl #5 misfire?

Have you checked for spark at the end of the 5 and 2 wires? Is there corrosion on the 5/2 coil terminals?

Have you ohmed out #5 injector(disconnect harness and attach ohm meter to the appropriate circuits?