re: Broke down in Alabama

code should show cylinder misfire.

What's oil pressure gauge showing?

Oil pump is cavitating because it's picking up air. It needs the oil pickup o-ring. Very common problem with the LS motors.

I live in Eutaw,would be happy to help him. I'll check this thread later and early tomorrow and give you my # or email if he needs it.

The Sellers are my girlfriend's relatives. They are good, trustworthy people.

I had a similar problem with mine. Was idling real rough, check engine light flashing off and on... cylinder was misfiring, but pulled up a code.
$80 for a new coil and changed it myself after I watched a YouTube video.

Why doesnt he have it towed to the nearest GM dealer?

I had a 2011 Silverado with the 5.3 and AFM. I was driving back from Florida to Baton Rouge and it started running really really rough in Mobile. I decided to keep on going but I couldn't go more than about 55 mph. I bring her into the shop and get told that my cam was rounded off because some of the lifters got stuck / push rods bent. Wiring harness had rubbed the insulation off, one of the engine mounts sheared off, and the other was cracked. That is why it was running sooo rough, the engine was shaking free. This all happened at 102,000 miles (right outside my 100,000 mile warranty).

The culprit was hypothesized to be a combination of bad gas and improper oil. I was working out of town at the time and driving 45k miles a year, so I was letting a local oil place change my oil while I was at work. I was too late for the settlement with Exxon to ask for anything and probably should have contacted the oil place. But I didn't feel like messing with it because they were so far away and I was working back in town at the time this all went down.

GM offered to cover 70% of the repairs up to $6,500 as a "good faith / loyalty" warranty because it was so close to my warranty period and I had been a repeat customer. They replaced the cams, push rods, lifters, engine mounts, wiring, and a head job. Basically got a whole new engine from the block up. Ran great afterwards and was just one of those freak occurrences. They gave me an additional warranty and I drove her for another 25k miles until my wife decided she wanted me to get a bigger truck to help her with her hobbies.

TL/DR: I hope it all works out for your friend.

The internal engine problem wasn't a freak occurrence. It was because of the AFM system. That's why GM paid for it

I had a flashing CEL on the Causeway once because I had a coil pack basically go completely dead. Not a good feeling