This may be a stupid question but here goes. Why does my new boost guage ( Autometer Nexus ) come with a new map sensor? The sensor is completely different from the stock one and in fact the stock wiring will not even hook up to the new one provided by Autometer. If the new map sensor is used then what do you do with the stock conector, just leave it hanging? Anybody that can explain this to me would be helping me understand greatly.

Thanks,

 

Presumably the gauge is electrical so has a separate sender. This does not replace the stock MAP sensor.

 

That makes sense! Too many late nights. LOL

 

Yikes, that could have been bad!

My Defi sensor is mounted at the firewall, right next to the stock MAP sensor. The vacuum line is T-ed to feed both MAP sensors. That way, the gauge is reading what the ECU is seeing.

 

Good idea with the "T"...will have to try it. Currently, mine is other side of firewall.

 

Wow, i can't tell you how many cars i have seen blow motors because of that "T". The ECU absolutlely NEEDS to see a clean, unshared signal from the MAP. Hook your boost sensor to any other vacuum port on the intake, but leave the hose to the factory MAP alone. Having another MAP bleeding off the boost signal will lead to incorrect LOWER readings and will lean out the motor. please just leave the factory MAP and hoses alone

 

The sensor is reading pressure, not air flow. Splitting the line with a y-junction should have zero effect on the pressure.

I've been running this split setup for 3 years, both with the stock ecu and the PFC. I was still plenty rich with the stock ecu and didn't have any problems with the PFC either.

So, you'll have to provide some actual evidence for me to believe your claims.

 

Agreed. My boost gauge is plumbed like yours. I tee'd it in before the stock MAP filter.