2003 chevy silverado mass air flow sensor problems

But what I do hear is not a hiss but a howling noise like a wind howl between the engine and my driver seat.

I can't hear great but have 2 people tell me they hear a hiss but we can't find it. Tried spraying around the engine with inj cleaner and maf cleaner to detect a vacuum leak with no change to RPMs or anything. Cleaned my original maf sensor with MAF spray with no luck, went to salvage yard and got a used which looked practically new and really clean for $25.00 and installed with no change in fixing the problem. Bought for 02 sensors from oreillys at $72.00 each which I have not installed and wish to return them due to having up to 5 people telling me wait or not install them due to their opinion of the 02 sensors not being bad but throwing 02 codes bank 1 sensor 1. Maybe not related but had to replace the heater hose assembly which was leaking at the plastic T connector but is still leaking from somewhere else.

Here is what I have bought and tried so far: Engine oil change, new plugs, checked all coil packs and all are firing using an old school test by loosening all rubber coil pack boots and checking for visual spark and all show nice consistent spark to each plug and cylinder but still getting misfire codes. After receiving my final stimulus check and still out of work and still in hardship I have spent nearly $500.00 on trying to narrow down from 1 to 5 discouraging random codes including p101, p300, p756, p135, p134. Currently after the battery problems months ago with battery replaced, I now have bad engine and fuel performance issues. Y'all helped months ago and still with many thanks. This message may be long but please read all if you have time. The truck listed above is a 4.8 extended cab 1500 plain model.

2003 chevy silverado mass air flow sensor problems