CEL 2000 Beetle Turbo

CEL light on. Local guy couldn’t determine what was wrong even other P1128 code. Had it for two days. 3 miles out of shop light came back on (paid $70 analysis fee). VW Dealer in Jacksonville says new MAF ($375) and clean injectors ($75)(paid $100 analysis fee)should fix the problem. Runs rough and seems to have lost its pep. Car is old but only has 11.5 on clock. Why would MAF fail? Any tips before I drop the big bucks would be most appreciated. HELP! Thanks very much.