I have around 155k miles, had a complete tune-up (including new wires,etc.) and the problem I'm having now is when I accelerate my engine shakes and once I take my foot off the pedal it smooths out. I have no trouble on starting it. Any ideas?

 

Yup, they misrouted the wires. You're getting crossfire between two wires. Have the shop re-route the wires and make sure they follow the firing order and prevent two consecutive cylinder wires from running next to each other.

Very easy for an inexperienced tech to screw up. But extremely important to follow the exact wire routing as factory.

 

For a moment there when I checked the wiring, 2 of the numbered wires didn't follow the firing order, but it turned out it was right they just used the wrong numbered wire for that cylinder.

I tried the key on & off ,etc to check any codes and I discovered a code 43 that can be narrowed down but basicly its a misfiring on a cylinder or cylinders....can that be I have a bad cylinder or can I still have a problem that can actually be fix without a rebuild?