Code I've never encountered before...

[Cody Forbes]

Patient is my white '87 5ktq w/ QLCC + fuel pump relay wired to run constant and boost at 1.1bar. Seems it got really pissed off at me tonight driving home from CiCi's. First I noticed the fuel pump intermittently getting loud, then going back to normal (1/4 tank of fuel). No driveability issues at this point. Was cruising along behind a slow moving vehicle at about 3,000rpm and the CEL popped on. I moved the throttle a bit and it went out, put the throttle to about the same position and after a second the CEL came back. Went to 5th gear and low revs and it stayed out. Right before entering my driveway I checked again, 3rd gear 3000rpm about 50% throttle CEL comes back on. 

Codes read out as 2221 and 2142. 2221 says "Vacuum hose to control unit sensor - Vacuum hose leaking, disconnected, or plugged". 2142 is a knock sensor open circuit code. The 2142 I've pulled out of this car before, but that 2221 I've never seen before on any of the 7 5ktq's I've owned. The vacuum hose looks ok to a quick visual inspection, and I've got a smoke machine at work I plan to check it with tomorrow (and check for debris on the fuel pump screen).

Any insight or BTDT's?

-Cody Forbes
http://www.5000tq.com
'87 5ktq - Fast.
'87 5ktq QLCC'd plus some
'86 5ktqCD
'86 5k
'86 5k