...thanks MATT3502, that's what I've found out so far. And according to what I have read I will be retracing my steps and try to find out the real culprit, since these popped up after changing the coil packs, for which I had to take apart the upper plenum and all related, and since I also ordered new wires that should arrive soon, well I had already planned to take it apart again.

But this time I'll order a new upper plenum gasket to replace, along with the Brake Servo Vaccum that broke long time ago, but had been solded in place with some Permatex, in the hopes that these two things had way too much handling and originated these new codes. If not I'll just follow down that list of "usual suspects" again.

I asked about these, to also get an idea of how much trouble was to be driving with them "logged", dince I do not feel much difference with my truck, I've had them on for two straight days. So any info on this particular issue would be important as well, thanks! ;-]#

 

I have been driving with 1171 & 1174 for about six months now. They do not seem to affect performance or mileage. I have replaced every vacuum line, the MAF and front o2's. At this point for me, I think it is leaky injector o-rings. Now that it is warming up here in the Northeast, I plan on tackling them, along with my valve cover gaskets.
There are a number of folks who sell refurbished injectors on ebay, and several have 3 to 5yr warranties.
When my Ultragague trips the code, I just reset it. sometimes they go away for a couple of days, sometimes they comeback multiple times in a day. FWIW.

 

Maybe a dumb suggestion but maybe your fuel pump ain't goin full bore. I had a chevy pickup do the same thing sputtering-wise. I was convinced it was electrical but turned out the fuel pump was going bad.

 

1. Quote:

   Originally Posted by matt3502

   I have been driving with 1171 & 1174 for about six months now. They do not seem to affect performance or mileage. I have replaced every vacuum line, the MAF and front o2's. At this point for me, I think it is leaky injector o-rings. Now that it is warming up here in the Northeast, I plan on tackling them, along with my valve cover gaskets.

...thanks again MATT3502! ...more the answer I wanted to read. I guess I'll tackle it like you have, although my codes showed up for the first time after replacing the coils, I'll start by replacing the upper plenum gasket and tightening those bolts properly, first. If it still shows up, then I'll move onto three orher things I've been putting aside for replacement since long, these are: replacing the $35 or so plastic Brake Servo valve, which the red thingy broke long ago, and have been keeping the line in with Permatex -might have to buy the line as well, the tip on the valve side broke too; the $100 or so corrugated hose connected to the SAI pump, it broke in a couple places and I have put some duck tape on it to "seal it"; and if I find it, the big plastic hose after the MAF, the thingy where the rubber hose from the IACV connects to also broke, so I've been holding it in place with lots of duct & electrical tape for quite some time already; but I doubt that any of these have triggered these codes, not even as pending.

So yup, knowing that 1171 & 1174 do not seem to affect driving and performance -for now- will give me some time to put focus on other repairs, ay least until I get to solve it. Unless someone else comes and rains on our parade! ;-]#

 

...thanks ZUKE! ...it was a thought that the initial fault of this thread could had also being "fuel" related, but ended up being a cracked plug; the issue was resolved by replacing that, and the rest of the plugs, out of precaution; wires will be replaced soon, a new Kingsborne set should arrive tomorrow, but I'm ordering a new Upper Plenum Gasket to replace the one I didn't replaced when changing the coil packs, which was one of the parts replaced trying to figure out why the sputtering, so wires will have ti wait for gasket to arrive. ;-]#