2005 cadillac cts runs rough after i change spark plugs

2003 Cadillac CTS Spark Plug Change 3.2L V6 - YouTube

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www.youtube.com/watch?v=8Pzcl-hJ9xQ
May 26, 2011 - Uploaded by Sandman Himself
2003 Cadillac CTS Spark Plug Change 3.2L V6 ... Cadillac CTSIntake Manifold Removal and Valve Cover Gaskets ... CheckEngine Light Flashing? ... CHANGING SPARK PLUGS AND WIRES GM 3.1/3.4 V6 - Duration: ...

Need to pull the spark plug and check it. The color and condition of plug will tell you a lot and also.run compression test.
Can't say what's wrong until checked out

check the coils,run it with hood open in the dark and look for sparks

I can think of a couple of things that may be the problem.
1. Reset the computer by removing the + and - battery cables, leaving them off about 5 minutes. Reset the cables & start the car. Sometimes they get out of computer sequence and have problems.
2. If you ran the tank too low prior to filling up, you may have some trash in the line caught in the filter.
I wouldn't consider the fuel pump, because when it fails you cannot start the vehicle at all.
Does your check engine light stay on? Does it run rough while driving, or do you just have trouble getting it to start? If it runs rough, it could be spark plugs or the control sensors on each spark plug.

I would have installed new spark plugs,all new coils
& mailed away the injectors to be ultra sonic cleaned
while the motor was out.

I wouldn't do compression,do cylinder leak down test
before, you ever install any motor, to check it's mechanical
condition

Replace front or upstream O2 Sensors, as I assume they
have over 100,000 miles on them

Check fuel pressure & use professional scan tool software
to look at ALL data

have the coils checked. they are now the distributor on ALL cars and fired by the cars computer.

Sounds like a secondary ignition problem to me. See if you can duplicate the symptom by using a spray bottle to spray a "mist" around the engine compartment.

maybe plug wires are not on tight enough, must crimp the lead ends of the spark plug wires on both sides. That is a common problem.

Sounds like he is right.
are you loosing coolant?
Other items that you may have noticed
Looseing coolant
White trails on the side of the block
Pull some spark plugs, do they all look the same.
Engine runs a little rough as it warms up and then is fine.

You might have crossed one of the plugs...another words, one of the plug wires is connected to the wrong spark plug. What size of motor do you have and I will post you a firing order picture?