Re: 98 Blazer chugging
if i were to wager a guess i would say the mass airflow sensor, its in the air intake between the air cleaner and the throttle body. the first 10-15 minutes the engine is running with a high idle, with a rich fuel mixture. once it warms up, it would then lean out causing hesitation under light load. another thought may be the o2 sensor in the exhaust system. have you checked to see if the air cleaner is dirty? my 96 blazer had a recall for reprogramming the engine control computer, maybe thats what it was supposed to fix. try a different dealership
i hope this may help a little