Just purchased a 2007 S with 108,000 miles. The check engine light came on indicating a misfire in cylinder 1. Took it to the mechanic and he has replaced the following:
Spark Plugs
Coil Pack
Fuel Injector
He drove it about 60iles and there were no issues. Today on my way home from work, light comes on again, same code, and then it would intermittently run rough, loose power, and the light would flash. Ran a compression test and got these results:
Cylinder 1 120
Cylinder2 150
Cylinder 3 148
Cylinder 4 150
Mechanic says the 120 is not enough to cause the misfire and he believes it is electrical because it is interermittant. He wants to replace the computer. Does this sound correct? I am at a loss here.

 

How about the plug wire? Swap it as a test

 

Is the 07 a coil on plug engine ?

If so, there are no "plug wires" like earlier engines.
If yes, did he check the coil connector and wires for broken or chafing wire ?

If it does have the large 7 (or 8)mm wires, then yes, the wires should have been replaced with the spark plugs and coil.

MIke