I have an 86 Iroc with a 305 in it. On my way home tonight I got a service engine light that came on so I'm like no biggy I will pull the code wen I get home. Well I barly made it home, 10 min after it started to spudder every time I hit the gas. Finally I got it home and pulled the codes. Code 21 Throttle position sensor (TPS) - signal voltage is high and code 33 Mass air flow (MAF) sensor - signal voltage or frequency is high during engine idle.

Any ideas on the first thing I should do. Any help I would appreciate.

 

I'd check the grounds to those, and the ecm.