P0171, P0174, & P0340

[ZwookY]

05 GT and I recently received these codes, P0171, P0174, P0340
Anyone know a specific reason that would trigger theses 3 codes together?
MAF maybe? IS the cam sensor totally unrelated?

Car runs but gets a little sluggish here and there for a couple seconds.
When I clear the codes, car runs fine.

This is the second or 3rd time in the last 2 years I've gotten these codes.

 

[StockishS197]

Any time P0340 pops up, the alternator could be suspect. What is your battery voltage while running?

Low voltage or a failing diode causing AC ripple wreaks havoc on these cars.

 

[ZwookY]

You’re right on. My brand new alternator that was replaced on Memorial Day failed the diode portion of the test.
Got a replacement but unfortunately it’s pouring rain.

 

[StockishS197]

You’re right on. My brand new alternator that was replaced on Memorial Day failed the diode portion of the test.
Got a replacement but unfortunately it’s pouring rain.

Keep an eye out on the replacement.

Most parts stores alts are reman and will fail again within a few years. I have found that the “new” more expensive ones do last longer, but the lifetime warranty for these more expensive units pays for itself on these cars

 

[ZwookY]

2nd new alternator passed both tests and everything seems fine, no codes in the little bit I've driven it so far.

I had to drive a few times yesterday before fixing and the codes appeared just minutes into each drive.
I "think" I'm good now.