2003 H2 Question

[PewterPower]

I have a 2003 H2 LUX with 88K miles on it. Recently replaced plugs with NGK and a new set of 7.5mm wires....new brake pads and both front hub/bearings have been replaced. I also cleaned the air sensor using electronic parts cleaner. Since replacing the plugs might have confused the computer, I also unhooked the battery for 30 minutes and then reconnected it.

When I start the engine cold, it seems to 'sputter' or jump....and the tach goes up and down....once it warms up, it seems to run better. I had my local shop check and there are no error codes. He checked the Fuel pressure and some other things and said that he doesn't see anything wrong.

The last time that I pulled a trailer (about 3K lbs) I had no power....

Any ideas ? Suggestions?