[Dual_ACRz]

The R/T & ACR PCM have the same settings for rev limiter, etc. as the other neons. The only difference is the speed limiter. In the '98 neon brochures I have, they call it 'unlimited speed', but you are, however, limited to *only* 120 MPH.

The Mopar Performance PCM (I'm running one in my R/T Coupe) has a higher redline (I think 7700 RPM), bypasses your EGR, and is noticably quicker over the stock PCM, especially when she's drinking 91 octane! Expect your mileage to drop off though, anywhere from 20-60 miles per tank

 

[ImperialCrown]

The Mopar Performance PCM also will pass state emissions tests as it stores OBD II monitors.
The knock sensor will let you use lower octane regular, but won't give you the maximum power.
The Mopar PCM is really only for 5-speed stick shift cars as it will light the 'ck eng' light in automatics. (It has no provision electrically to lock up the torque converter clutch).
They show up used from time to time.