So I just got my 89 suburban 454 back from the mechanic. He really made a big difference and the car runs great except when at a stop with like 5% throttle or less. It won’t stall but it bogs down a bit and will kinda lope for a second or two when you let off the gas then will idle or run fine. If you push the gas down just a bit more than the 5% it accelerates just fine or if you give it just a bit of throttle when already going say 15+ mph it also accelerates just fine. Also the engine light turns on and off or flickers basically the whole time the car is on but doesn’t affect the cars performance. My mechanic seems to think it’s the ecm. Any ideas fellas? Thanks