My dad drives a 1988 chevy 2500 light duty. It has a brand new 700r4 and a 350 with almost 200,000 on it. This is his only vehicle and he needs it for work. He said the truck was fine driving to work but when he went to leave the truck started to run wierd. First off it seems like it has an rpm cap like it can only get to a certain low rpm. He can only do like 15-20 mph. The truck has no power. At idle it slows down then picks back up. It keeps doing this like a wave. If he revs up the motor slowly he can get it to rev highish but the second he puts his foot down the rpms drop and it runs bogs sort of. He tested the tps and the map sensor and they tested fine for voltage. He has a newer coil. I had him blink out any codes and it flashed 12 3 times then came back with a code 44. He replaced the o2 sensor although i think that that code only appeared because of how the engine was running. Tomorrow he is going to get the icm tested at the store. What are some things i can tell him to check? Does this sound like its in limp home mode. So it ran good when he arrived at work and instantly ran bad when he started it up to leave. Thanks
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