I believe the only "poor man's" way to read the codes is thru AutoZone, which scans for free (except in CA).
If you ask around locally, some shops will scan for $20-$30.
The TPS (throttle position sensor) costs around $10-$13, and is very easy to replace.
Steve - TCCoA member
2003 Crown Vic LX Sport
1995 T-Bird LX 4.6 retired at 247,888 miles
Thanks for the ride !