Where do I start? P0172 code
 

I'm going to apologize now for the lengthy post
But this has been an ongoing problem for the last few months so there's a lot of info to give
Every time I think I've found and solved the problem, it either stays the same or gets better for a few days then goes back to the same issues...
Here goes...
My 96 Cutlass Ciera 6cyl 3.1 threw a P0172 code 2 days ago
But as I said, the problems actually started months ago
It 1st started when, while my car was warming up, I heard it start to 'sputter' then it died by the time I got to it & wouldn't start again
Come to find out, I'd let a friend drive my car and they brought it back dead on E :mad::mad::mad:
Checking the guage never occurred to me because I don't ever run it that low
Regardless, it did seem like it went thru a LOT of gas considering the short time he used it...
Once I put gas in it, it seemed fine
I took it to the store (5 minute drive), came out, started it and it died immediately
I had to try 2 more times to get it to stay started
After that, sometimes it would start right up, other times I'd have to give it a little gas when I 1st started it
BUT, that was only once it was warm
When it was cold, it started fine
I changed the fuel filter thinking maybe gunk from the bottom of the tank got sucked into it when dipstick ran it out of gas
That didn't solve the problem
Then I noticed that my gas mileage had gone down from 25-28 mpg to 16-18 mpg
I cleaned the MAP sensor & changed the fuel pump
It seemed to get better for a week or so then it was right back to the same problem
It's still fine when it's cold but once it's warmed up, same old same old
Also, the idle isn't steady especially once it's warm...like I'm tapping the accelerator very lightly over and over
**I promise, I'm almost done**
Tbh, it always started by the 3rd try, ran okay once started and, aside from the gas mileage, wasn't really a problem
So I ignored it (now who's the dipstick??) :thumbup2
Then it threw the code the other day, & I figured I better get to the bottom of it
So today I took the air filter apart, checked the MAP, then my plan was to see how the throttle body looked
As soon as I took the hose thingy off the throttle body, I saw small pieces of debris (1 or 2 pieces of grass, some dirt and pieces of bugs 🤢) on the mesh screen that is in front of the throttle body
I checked really close with the camera on my phone and saw the screen was pretty much clogged with what looked like really fine dust
I took a Qtip & sprayed it with Seafoam cleaner (the Qtip, not the mesh) and tried to clean it
It was still plugged so I used a vacuum very gently on the mesh
Now I can see the throttle body "flap' if I use my camera but not well enough to see if it's gunked up or not
So, where do I go from here?
Should I clean the throttle body according to the instructions on the can of CRC maf cleaner I have?
Also, from what I've learned from Google & YouTube, that's a 2 man operation...one person to get the rpm's up and one to spray the cleaner
Do you really need 2 people?
If not, how do I do it by myself?
Or, should I go in a different direction??
There, I'm FINALLY done!!!
Phew
Whoops, almost forgot, please keep in mind, I am no mechanic
The only reason. I do any car repair is because I'm really cheap
The little I do know, I learned online
So I need detailed directions
Pretend you're talking to a 5 year old...
So...
Thank you for wading all the way thru my babbling on and on I appreciate any help and/ or suggestions

Spray MAF cleaner while the engine is shut off. Let it soak.

Find how grass and dirt got to the flow screen.

Then, once those are done, let us know how it is running.

Also let us know how many miles are on it, as well as how many miles are on the current set of spark plugs.

We might ask you about fuel pressure soon as well.

Unplug the sensor and see how it runs. Decent? The sensor is problematic and may be bad. Also, if you tap the sensor while engine is idling and it causes the engine to skip the sensor is bad.

I sprayed MAF cleaner thru the mesh that's in front of the throttle body and I let it soak
But the mesh is so small I couldn't tell how far back into the TB it went before it poured right back out

I checked on how the debris got into/on the mesh...is there supposed to be a pre filter before the air filter?
Because where the air comes in just behind the grill, there's nothing
I can stick my hand from inside the filter housing all the way til where the air comes in
Seems like there should at least be a screen?

When I 1st started it, it was fine...a small jump when idling but I'm not sure if I would have noticed if I wasn't listening for it
Then as it warmed up, it got worse and was way more noticeable
Worse than it's ever been

There are 128763 miles on the old gal
Now comes the embarrassing part
I shouldn't even admit this...it's something you should only tell a priest to avoid public shaming...but here goes...
I had a misfire about a year ago and set out to change my plugs...but it was such a freakin nightmare that I changed the plug w/ the bad wire, did 2 more, lost my temper, every bit of patience I had, and called it a day
So 3 plugs have about a years worth of miles on them If I had to guess on the other 3, I'd say no more than 2 1/2- 3 years
I've only had the car for a year and a half

Checking the fuel pressure will require a trip to the auto parts store...which means I'll have to walk or ride my bike
So if it does come to that and no one ever hears from me again, that won't mean I solved the problem
It will mean that I chose to ride my bike and my heart exploded because I forgot how old and out of shape I am
Not to mention that every single solitary freakin road in this town is up hill
BOTH WAYS!!
There will be other helpful info when I answer the next reply but I've already blabbered enough in this one I figured your eyes might need a break

I didn't unplug the sensor until it had warmed up a little and the idle was jumping worse than it ever has
I did tap it when I 1st started the car and as far as I could tell, it didn't have any effect
I did take the sensor out and the "flaps" & wires that go across it look...off
​​​​Theyre not symmetrical, if that makes sense
But I'm not sure they're supposed to be
Since unplugging/tapping it didn't have any affect, can we assume it's ok?
It seems like last time I tried to post a pic on another post I couldn't figure it out
But if it'd help to see what I mean, let me know
Oh, and the sensor is only about 1 or 1 1/2 yeara old

It should have an air filter in the cannister here:

https://cimg5.ibsrv.net/gimg/www.gmf...8e69b3ccd0.png

I'd say if you don't know how many miles are on the other 3, then they might have a million on them. That PCM can't compensate cylinder by cylinder, so it would be out of whack for half the cylinders no matter what.

I know I said I'm not a mechanic, but, I did not say I was 🧠 dead lol
I KNOW that the air filter housing holds an air filter
It just seems like there should be a pre filter to keep really big stuff like twigs & other debris from getting to the air filter

Actually, I bought the car from friends and the plugs were changed about 2 years before I bought the car
I do see your point though so I will grudgingly change the other plugs
But since it's been so long since I changed the plugs I did, how likely is it that the plugs are part of the issues I'm having now?

Is it coding at idle or cruise? Fuel pressure? You're still chasing a PO172?

Okay cool. From your description I thought it didn't have a filter installed.

Not usually. Manufacturers generally rely on the air filter for all of that. If it were something more off-roady it might, but even then I've seldom seen this from an OEM.

Okay two years isn't so bad, depending on actual miles of course. What make/model plugs did they use?

It would be more likely that wires or coils would be an issue than spark plugs. Depending on miles and make/model of plugs installed.

I'm assuming that by "coding" you mean throwing the P0172 code?
I've never had my check engine light show intermittently...once it's on, it stays on til cleared or fixed
But as I said, I can't even call myself a backyard mechanic so I'm not 100% sure I'm interpreting that correctly
Regardless, the check engine light was on whether I was moving, idling or parked
And yes, I'm still chasing the P0172
Unfortunately, I accidentally erased the code and I'm really leery to drive it now because the idle is so irratic
I'm sure the same code would show up because I certainly haven't fixed it
I haven't checked the fuel pressure yet
I'll have to get to the store to get a testing kit
If I test the fuel pressure, will that help narrow down the problem?
If it helps, the check engine light came on when I started the car, not as I was driving