Check engine light (codes)

[FloridaState]

So my check engine light has been on for the last few days, so I went by Autozone just to get the codes it was throwing. I got P0174 and P0171. The guy said the fuel/air ratio is messed up and it could be anything from an O2 sensor to bad MAF.

I just wanted to see what your guys' thoughts are, since I trust you a lot more than the Autozone guy.

I have to travel to rural Georgia, on backwoods roads with no cell signal, this weekend so I want to make sure this isn't something that's going to leave me stranded. If anyone has any ideas/suggestions/comments, they'd be much appreciated!

Thanks in advance!

 

[swetrid]

What engine? If it 4.0L SOHC probably is intake gaskets.

 

[FloridaState]

What engine? If it 4.0L SOHC probably is intake gaskets.

Sorry, I should have specified. No, it's the 4.0L OHV with about 85k miles.

 

[Hartman]

Those are very common codes amongst all different types of vehicles. The first thing to check is for vacuum leaks. Clean your MAF. Make sure all your maintenance is up to date. Then go from there.

Typically those codes are triggered because unmetered air is getting into the engine.

 

[FloridaState]

Those are very common codes amongst all different types of vehicles. The first thing to check is for vacuum leaks. Clean your MAF. Make sure all your maintenance is up to date. Then go from there.

Typically those codes are triggered because unmetered air is getting into the engine.

Had it checked for vacuum leaks a couple weeks ago when it was in the shop for an unrelated matter, so I don't think that's the case. I cleaned the MAF today and the light went off, but that's because I had to disconnect the battery. We'll see if it comes back on in the coming day(s).

Thanks for the response! I'll check back in a day or so.

But regardless, do you feel as if it's okay to take the X on a long drive this weekend? It seems to be no big deal, but I want to be certain. As I said, the route I take to get to Ft. Benning is extremely desolate with little to no cell signal, so getting stranded would really screw me. lol

 

[Hartman]

You should be fine, but your gas mileage will suffer depending on the root cause of the CEL

 

[FloridaState]

Okay, yeah the consensus seems to be that it'll be fine.

The light hasn't come back on yet (knock on wood), but it's only been a day. We'll see, I suppose.

If it does come back on, should I get a new MAF or what? Even though it's nothing detrimental, I still don't want to drive around with my check engine light on until it decides to finally go off.

 

[Hartman]

First step would be to clean the MAF

 

[FloridaState]

Already cleaned it. As best I could, any way. I don't have the torx bits so I couldn't take it out completely, but I did get the section off (tube and all lol) and sprayed it pretty good. It still hasn't come back on (knock on wood) so we'll see if that lasts. I also just recently put in a K&N air filter, could that have thrown something off? I disconnected the battery after I installed it, to reset the computer, but maybe it's still throwing the fuel:air ratio off.

 

[Joe Dirt]

Yes- those @%^$#! K&N filters throw oil on the filaments. Cleaning should be good- what did you use?

 

[FloridaState]

Yes- those @%^$#! K&N filters throw oil on the filaments. Cleaning should be good- what did you use?

I seem to have misplaced the can...apparently it grew legs. But I know it was MAF cleaner, it said it right on the label.

 

[FloridaState]

The f&*^ing light just came back on today.

 

[Guit4rG0d]

I had the same thing starting about a week ago. I ended up having to replace the MAF, which got the light to turn off, but not for long. Ive read that Vacuum lines would be the #2 problem, but other than that elbow from just past the air intake to the engine, I have no idea where to look (and have no idea what that diagram under the hood says).
Anyone have any good photos for us visual learners of the main vacuum lines to check?


PS:

You should be fine, but your gas mileage will suffer depending on the root cause of the CEL

I was getting about 50 mi on a 1/4 of a tank
It doesnt seem to be that bad now after the replacement of the MAF, but its still under what i normally get

EDIT: its a 4.0 SOHC

 

[FloridaState]

I'm going to bump this as I still haven't solved the issues. I've had the O2 sensors changed, fuel injectors cleaned, fuel filter changed, etc. and nothing seems to be working.

I took the MAF out and cleaned it thoroughly, then replaced the K&N filter with just a normal one, to see if that was the problem...that lasted about a day, then the light came back on.

So anyone got any suggestions? Nobody can seem to figure out what it is, and I really don't want to continue to dump money into it to no avail. My cousin had similar problems with his F-150 and it ended up being the EGR valve, could that be it?
It runs extremely rough when it's cold (like freezing temps and below), and dies semi-frequently --especially when idling. It doesn't exactly run smooth in warmer weather, but it seems to be exacerbated in the cold.

ANY advice would be greatly appreciated.

PS- sorry for my scarce posting as of late, but my classes have just been eating up all my time. Hoping to change that.