I just bought an 88 turbo II and just installed a cone intake filter here are my issues

• slightly rough idle
• boost gauge non operational

I suspect maybe a turbo leak, any other thoughts?

 

what hoses did you knock or block off

 

None that I'm aware of... I followed the instructions, and double checked everything. Is there 1 in particular I should check?

 

if the factory boost meter isn't working then your map sensor is unplugged or broken.

 

I assume that is the sensor plug that plugs into the MAF?

 

So I checked things out and the MAP sensor is working fine... There are also no hoses kinked, blocked off, or knocked off... Any other ideas?

 

put the stock intake box back on just to make sure. If it does the same thing then you knocked something loose.

Check the pressure sensor hose, it can come off at the engine side as well as the sensor side. If it is unpluged/broken it will cause the ecu to not get a correct reading which will make your car run rough and the boost pressure will read 0 iirc.