Error codes - engine stalls

[Jagernauth_Stephen@bns.attmail.com]

I changed my 5ktqw's air filter and fuel filter last weekend and the 
car started stalling
and will not idle since.  It was perfect before.  I loosened the solid 
pipe from the
turbo and loosened the large 5" hose clamp holding the large air plenum above
the air filter housing in order to replace the air filter.  In doing 
so, I may have not
tightened it properly introducing an air leak though I've rechecked it 5 times.

Anyway, my engine light is now flashing intermittently so I dumped the codes
using Phil Payne's excellent summary and got these in the following sequence:
2322, 2321, 2222

2222 Pressure sensor   Control unit's pressure
                       sensor defective        Replace unit

(2312 Coolant sensor    Open or short circuit,
                       defective sensor        Sensor and cables)

2322 Inlet air temp.   As above                As above

1. What pressure sensor is referenced in 2222 (boost pressure?)?   Can 
it be changed
w/o replacing the entire control unit ($ouch)?
I have a stiffer WG spring seeing 1.8 peak with the fuel pump grounded 
at the ECU.

2. Where is the inlet air temp sensor?

3. What is code 2321?

I have to drive the car by feathering the gas at every stop and my wife
can't drive it at all w/o stalling so I'd appreciate any input.

Thanks,

Steve Jagernauth   jagernauth_stephen@bns.att.com
'87 5ktqw and 5kt
'74 911/3.0