Searched and found a few threads but most were related to a new CAI.

My light came on driving to the dealer for the axle recall (both were replaced - Yay!). Dealer told me that the code was p0171 - I was guessing that it was a p0141 because that one had gone off earlier thanks to a cheap o2 sensor I purchased. A NTK downstream sensor on it's way. Fuel tank down to about 1/4 tank just when the light went off. Gas in the car is old (long story but was an auction car that was likely sitting for about a year). Car has 176k miles with a pretty bad maintenance history.

Dealer is suggesting valve adjustment first and then injector replacement if that doesn't work. Said the long and short fuel trim numbers were bad. $500 for the valves and $1000 for the injectors. Note - only paid that much for the car itself.

Filled up the car on the way home with a bottle of Techron. After the third start cycle - the code went away.

Any thoughts? I am wondering if a fuel pressure issue although at the mileage wouldn't be surprised if injectors gooped up.

 

I believe I got the same code in november. I tightened plugs (I'd anti-seized them when installed a few months back and figured when i saw an issue that'd be the problem), adjusted valves (it's been like a year or two), cleaned injectors.
Things 1 and 2 didn't seem all that bad, which is why thing 3 was added. No real issues there either.

The plug that broke free with the least force wasn't in the same cylinder as the valves that had excess gap.
Honestly, the problem could have been bad gasoline from the local BP, but the services rendered did resolve the CEL. As you know, lotsa stuff goes into the fuel ratio, so bad gas + iffy valves + not quite tight plugs (no vac leaks, the rubber seems great) + goopy injectors could equal a light, and resolving any one of them could fix it. I never sweat addressing plugs and valves on the GE. Even if it isn't the problem, it runs better afterwards.

The cool thing about doing valves here is that the gasket is reusable, so it doesn't cost a dime. Just get the silicone off of it and the spots where the head mates to the timing cover and reseal. Also.. theres no reason to mess with coolant (the throttlebody). It's not in the way of plenum removal once you unbolt it.

Edit: I'd recommend knocking out the cheap stuff first. I don't think @julianachos ever replaced his fuel pump.
If anyone has, I haven't heard of it.

 

Thanks. I had replaced the plugs/coils when I bought it because of misfires. When I went to change the plugs I could twirl the socket with my fingers because 3 of them were so loose (but not the cylinder with the misfire code). Good to know about removing the throttle body - it was a pain to clean (I originally thought that was the problem until the tech said fuel trims were way off).