This is my first posting and I am not mechanically inclined, but do want to pep up my 2005 Crown Victoria LX Sport which is completely stock except for a K&N Cold Air Intake. It runs great for 130,000 miles, but is sluggish.

I have read many articles about improving my 4.6 SOHC engine performance, but most of them require more investment than I can afford. Would the following plan make sense for "low budget" improvements:

1. Buy a Diablosport Predator.
2. Change from 87 Octane to 91 Octane.
3. Re-Tune to maximize performance of the K&N System and Higher Octane.

Stop and Evaluate by "Seat of the pants". If OK, stop spending money.

4. Buy Accufab 70 mm Throttle Body and Plenum (P/N F7046K).
5. Re-Tune to maximize performance of three (3) items.

Stop and Evaluate by "Seat of the pants". If OK, stop spending money.

6. Buy 2.5 inch "Cat-Back" system.
7. Re-Tune to maximize performance of four (4) items.

Stop and Evaluate by "Seat of the pants". If OK, stop spending money.

Would you recommend a different sequence or a different plan?

Thanks in advance for helping the "new kid on the block".