swapped intake manfiold now burning HOT catalytic converter!!! why???

I got a 92 gs w/ the following mods:
-aem cai intake
-dc headers
-2.5" custom exhaust piping
-dsm injectors

Earlier today I swapped out my intake manifold for a '95 LS IM. Made sure everything connected fine - vacuum, coolant, and fuel lines plus sensors. Started up car and idle was kinda high but it gave me a code 16 error. Checked all fuel related items and all seemed okay. Drove it around the block and car would not rev past 3.3k - it just bogs past that. Came back home checked everything again and could not find anything wrong. Reset ecu and still have same problem. I let the car run for about 5 mins and nothing smoke. Suddenly smoke all around the car. Looked below my car and saw that my catalytic converter was red hot. Crazy!!! Also, from my apexi vafc, I notice that I’m not getting any intake pressure as well. Made sure there was no vacuum leak but still nothing.

So to sum things up - After swapping in a '95 IM I have a few issues:

  1. error code 16
  2. burning RED HOT catalytic convertor
  3. no inake pressure

Please!!! Need some honda experts!!!