meanjoe

https://www.lsxceleration.com/alternators/

Try these guys for a new alternator.

stefuel

Put the battery on a charger to bring it back up to snuff. Remove the alternator and bring it to your local auto parts supplier that has the ability to test it. You must be sure it's the alternator before you spend money on something that does not correct the issue. A alternator that doesn't charge is not always the alternators fault. A old alternator that is not being commanded to charge will not be corrected with a new alternator that is not being commanded to charge

heavychevy357

Well new battery, new alternator, new spark plugs(NGK TR6IX), new AC Delco plug wires... still getting the P0171 code and the car is still stumbling at 2-2500 rpm then just quits stumbling and flies!

on my WiFi OBDII scanner it will show everything normal and then randomly fuel trims shoot up from -10% to 53% on short term and up to 24% long term. I also notice timing advance in cylinder 1 goes up to 30-33* from 12-14* before its doing this.

Back to being stumped. Thinking I may invest in EFI Live or HPTuners to see what’s going on more in depth.

Maintaining proper voltage now though solid 14.0-14.3 Volts.

stefuel

Would start at the MAF. Make sure it's clean as well as it's connections.
Then I would look for vacuum leaks. Inspect the PCV system. Get a can of starting fluid and carefully dust around the engine while running. IF any starting fluid is ingested through a vacuum leak, the engine will rev up slightly. Also could be a bad o2 sensor

MTPZ06

Hopefully something else didn't get fried.

heavychevy357

I am installing a new o2 sensor on the driver side. Lifted the car today and took the o2 sensor off and it was showing some copper through a little knick in the blue wire.

heavychevy357

Well it was the O2 sensor. Driver side was bad. Swapped it for a new one. Car ran good. No stumbling, no codes. Hope it stays well.

e46m3c

nice one!

Tech

Glad you got it all sorted out and the repairs weren't too involved.