Jarred767

Cool, thanks! I've found a few of the different threads on here and through Google with kinda similar issues or with the error code I now know, so I've got a list of a few things to check like hose leaks, MAF sensor, and a couple others. Hopefully it's one of those and not the pump.

After trying to think about possible causes, I did do seafoam (just directly into the tank) about 3-4 tanks before the issue arose. I also did a deep clean on the engine bay about a week before issues started. Any chance either of these could be the culprit or help narrow down causes/things to check first?

donbrew

If you used a pressure washer, that could have either blown something loose or infiltrated a connector.

aradmahogany

Not to butt in, but in the future, I would advice against any cleaning under the hood. there just isnt really a point to it other than "looking good" but there are so many electrical components under there that arent meant to be soaked in water that you may end up with a pretty but malfunctioning engine bay. You dont want to get the fuse box or coil packs wet, or the alternator or any other component under there for that matter.

Jarred767

I doubt the cleaning had much to do with it (and it makes it so much more enjoyable to work under there if it's not filthy). Definitely no pressure washer involved, just a thorough cleaning with degreaser and damp towels. I detail cars for a living and have never had an issue with these very conservative methods; it's unlikely that caused anything unless I may have bumped something loose, but anything's possible. I hesitated even mentioning that, but oh well, bigger problems.

Anyways, I had pretty knowledgeable friend look at it with me today and he was pretty perplexed as well, I ended up killing the battery cause it just kept dying every time it would start. Finally with it being jumped, it started and held. Once it was running consistently it seemed pretty close to normal. He guessed it was most likely a vacuum leak, issue the MAF, a clog in a fuel line and this was before I told him the code. Since those all align with p0171, it sounds like that's where I'll start.

If anyone else has any other ideas, please feel free to share.

Jarred767

Cleaned the MAF sensor last night..... no luck

Gonna look for vacuum leaks today to see if that's the cause.

Oldblue

Check the flexpipe for leaks, you've ensured the purge valve is working, you cleaned the MAF sensor, so please check for exhaust leak prior to the #1 O2 sensor.

Jarred767

Cool thanks! I'm working my way through this list (checked the EVAP first though)
-The MAF (Mass Air Flow) Sensor is dirty or faulty
-There could be a vacuum leak downstream of the MAF sensor
-Possible cracked vacuum or PCV line/connection
-Faulty or stuck open PCV valve
-Failed or faulty oxygen sensor (bank 1, sensor 1)
-Sticking/plugged or failed fuel injector
-Low fuel pressure (possible plugged/dirty fuel filter!)
-Exhaust leak between engine and first oxygen sensor

So what you're saying is do the last thing before O2 sensors?

And if I get that far, the fuel filter cannot be changed, is that correct? Thought I remember reading that somewhere.

donbrew

No PCV. Just a tube.

I would not worry about the O2 sensor, unless something else points to it.

Injector is a reach.

1. an air leak somewhere between the MAF and the #1 O2 sensor. Including the sensor bung.
2. fuel pressure, filter is part of the pump. Easy & cheap to check.
3. injectors. Cost to check is about the same as replacement, about $120. Low on the list of causes.

Of course, a cylinder pressure test should be done to rule out a burned valve, before you throw parts at it. That would be included in #1.

Oldblue

And you could just listen for any exhaust leak up by the flexpipe, no money spent, unless you found the leak.
I'm with Don , the fuel pump and injectors are way down the list of common cause of the code.

Jarred767

Alright new development... Went to start looking for vacuum leaks and really got into it to see exactly where I'd want to start spraying starting fluid. Before I got to anything though, I found some dreaded rodent droppings. Ended up that it was quite a bit, but quite old and dried up. Mostly located just passed the MAF sensor all sitting on the engine under the air filter box.


Took air filter box off, vacuumed everything up really good using brushes to agitate it. Put it all back together, and now I can't get it started at all, even with a jump. My guess is that all of that crap may have been hiding a vacuum leak. I disturbed just enough of it to cause my previous issues when I cleaned out the engine bay a week ago, and now with all of it gone, the leak is even more exposed, thus the reason why it won't start.

Is this even logical?

If so, how do I find a potential leak now without being able to start it at all? Thanks again!