Split in Manifold Pressure.....Need Help

[JeffAxel]

could just be a gauge issue, what does it read with the engines off?? Both sides should read atmospheric pressure. If they read different, you have found your problem. If they are the same with the engines off, then while it could still be a gauge problem, I would keep looking for induction leaks. Just my .02, keep us informed.......

[stackj]

I chased a manifold pressure problem on my front engine for about two years... Finally found a split nut on the manifold pressure copper line where it went through the firewall.

[Paul462]

Is that plane turbocharged?