2173158 is the 2008 2.4 injector pn
12613163 is the 2009 2.4 injector pn
both show 43 ps flow rate

The difference being the 2008 isn’t flex fuel and the 2009 is.

 

Thanks. I'll copy this when I take it in to the shop.

 

Interesting. All the things being equal, normally a flex fuel car would need a larger injector. Maybe it already had plenty of capacity. Then I would expect the only difference to be ethanol compatibility in the seals? But I don’t have a very good understanding of how injectors work.

 

The computer controls the duty cycle of the injectors.

 

The flex fuel injectors are able to withstand the ethanol

 

Pretty sure flex fuel needs to pump more fuel. Could be the non-flex shield injectors had surplus capacity.

 

Slight update. The P0172 code did go away after my wife drove it locally while I was away, like you guys predicted.
Unfortunately it's sounding even rougher now.
And the local mechanic I was going to take it too can't get to it for over a month.
Father-in-law is going to have someone look at it hopefully today.
He's going to check the plugs and coil packs and the O2 sensor before cracking open the valve cover.
If he can't figure it out, I have a few calls to make to local shops with good Google reviews.
Thanks again for the help.

 

If no codes, don't let them throw parts at it. Most likely the timing chain is slightly stretched, not enough for a code.
Popping the valve cover is not a big job, usually don't need a new gasket.

 

The codes this morning were the intake and exhaust camshaft position sensor again (p0014 & p0016) and knock sensor p0326 and MAP sensor p0106.
The mechanic heard the whole history of the car, then I started it up for him. He said, "shut it off before it breaks. I can hear the timing chain slapping around under there."
So he's going to hopefully have time to open the valve cover this afternoon.
I already ordered the parts listed on one of the threads about replacing the timing chain (cloyes kit) and water pump (ac delco) . He is ok using them, so I have a good feeling about him so far.

 

P0016 means timing chain not VVT. You forgot to mention that earlier.
The MAF and Knock sensor codes probably come from wires or fuse. I guess they could be related to the bad chain.