I bought an 01 z24 off a friend of mine he got in a trade and was suprised when I popped the hood and it had the old pushrod 2200.I looked up the vin and it was originally a 2.4.I'm not interested in swapping it back or anything, I just want to know what they had to change to do it or if it was a pretty simple swap.Also I only got a key with the car but when I decoded the vin it said it had remote keyless entry, would that still be in the car or was it part of the 2.4 ecu?
Keyless entry is controlled by the body control module. It's unlikely that they changed that for the swap unless they re-wired the entire car, which isn't necessary.
The swap is relatively straight forward. It does require a transmission swap as well. If it's manual, half of the case could be swapped to get the correct bell-housing (though it's unlikely that someone would go through the trouble). The actual transmission is the same other than the bell-housing that's part of the case. The engine harness, PCM, hoses, belt, engine mounts, exhaust manifold and downpipe are really all that's different. A 2.4 PCM could even be used to run a 2.2 but it would require tuning via HPTuners or another software packages that supports this platform.
"In Oldskool we trust"