S25 SRT

awhile back a set of headers were fitted to me moter.
no problem there but the lambda sensor hole needed blanking as its located on d/pipe. fitted a stainless steel bolt but it blew out en route home!
so basically had a 1.5-2inch hole in system losing pressure and blowing like an asthmatic tank. (sounded like a tank too)
i had to go away for a few months due to work but asked friend to turn it over once every 10days r so for a few minutes. no problem, i got back went to do some other work on it that neede doing (cosmetic) turned it over for 2 minutes no hassle.
following week it wouldnt start-not even turn over?! has the ECU performed a safety feature i aks u?
how do i sort it, also the CEL light came on self diagnosed it and i get codes 23 and 12 (MAF Sensor and ignition)
it was going to subaru here in cyprus for cambelt change, leeds and plugs anyhow but i like to have a bit of mechanical understanding so i can explain to the mechanic what to look for.