k i have a p0068 and 69 popping up. i know what they are but i need help with one thing. i was watching my boost gauge to see if i was having vaccum leaks or anything that would cause pressure changes hoping it was just a intermitent problem. well i notice its spikes to 0 and will sit at 10hg vac at idle then drop to around 21sih. so i switched the interceptor gauge over to read boost and its reading fine. my question is that..is the boost from the interceptor reading from the map or another sensor, i know that sounds retarded..or does the the stock boost gauge read from the computer once the map sends a signal back, or does the stock boost gauge have a direct wire to the map? basically is the stock boost gauge reading from the computer or from the sensor directly? im trying to diagnosis if the boost gauge is taking a dump on me. its been perfect until these trouble codes. now also i cannot go into boost at all or its instant limp mode. ill clear the code and boost again..limp.... so its a definate issue. im putting it on a tech 2 tommorrow and using alldata to do a complete diagnostic but i dont wanna look up a wiring diagram for the boost gauge.

 

seriously nobody knows??

 

none of your readings are analog. You need to read analog boost, not pcm boost.