Re: only revving to 4000 RPM SRT6
Yes, it is mounted on the driver side fender well. The 'normal' cause of this code is burnt relay contacts on the air pump relay in the K40 ( RCM ) module.
You can send the RCM to tighed1 and for 20 smackeroos he'll replace that relay, solder the troublesome connections and install the "me so horny" mod.