Idle Problems....CODES inside

[extremetrek]

Hey Everyone!

Original thread: here

So I pulled my codes and heres what I got...

Continuous Memory:

157 Mass Air Flow Sensor Fault at Low Voltage
158 Mass Air Flow Sensor Fault at High Voltage
172 Hego (H02S) Sensor Lean
176 Hego (H02S) Sensor ALWAYS Lean
181 Unable to lean part throttle (said trucks only???)
189 At rich adaptive limit/system lean


KOER

172 Hego (H02S) Sensor Lean
136 HEGO (H02S) Alway Lean

Does this explain my terrible idle, terrible knock on start up and overall weirdness? Does it mean that the MAF is broken, needs replaced, cleaned, what? I also ran a cylinder balance test and got code 90 (system ok) I am really hoping this gives the answers I am looking for and am counting on you stangnet to come through one more time. Thanks in advance!

 

[extremetrek]

I also have a vacuum gauge...useful little tool it seems...but where would I hook it up on my car?

To add: In the intake tube (where the MAF is) there is a small amount of oil...apparantly coming from the hose connected to the oil filler tube...what does this mean?

 

[extremetrek]

Another reply to my own post...the car seems to run better with the MAF disconnected. I am thinking a bum MAF creating a lean condition? Any way to check?

 

[mo_dingo]

start by checking the maf for buildup. If it's all nasty, clean it, reset the computer and drive it again.
Scott

 

[HISSIN50]

I'm with Scott there, esp if you have oil seeping around the PCV vent. Check your PCV valve and screen - the little hose on your inlet should mostly be used to allow air back INTO the crankcase (sans at WOT, where it expels crankcase vapor). Oil residue suggests that pathway is working too hard.

If you have a MAF issue, the O2 codes could stem from that (the system cant figure out what's going on, due to the range of MAF codes). I might also check the voltage readings at the MAF - it seems to me that Scott has posted some good info about that in the past.

I'd also perhaps just clear the KAM and drive it a bit and see what it does. I know mine runs best with a clear KAM (before it adapts and leans out).

Good luck.

 

[extremetrek]

The MAF doesn't look bad to me at all...I have an oil seperator installed past the PCV and I am going to empty that and replace the PCV valve (who knows when that was done last). I'll look for info on checking the voltages off of the MAF...and whats a KAM and how do I reset it?

PS: Anyone know the size of the idle stop screw? I can't seem to adjust mine and it would be nice to rip it out and put in something that would work...thanks!

 

[HISSIN50]

I think Scott knows the thread size for installing a throttle stop screw. I just use needle nose pliers.

Looks can be deceiving - something has to be up with your MAF to spit those codes.

To clear the KAM (Keep Alive Memory), disconnect the battery and turn on the headlights for 20 seconds. Turn headlights off and reconnect the battery.

Do you have the filter element in the separator? Mine had clogged up and was presenting a restriction to flow. I had noticed that the accumulation of oil almost stopped and the oil in the separator was being aerated violently while the car idled. I removed the element and the issue abated. Some folks clean the elements but that's a pain IMHO.

Good luck.

 

[extremetrek]

Yeah I agree that something is definitely wrong with the MAF and I am going to remove it and clean it VERY thoroughly, as well as the electrical connectors as soon as I can get back to town. I don't know if there is a filter element in the seperator I will check, but I know it prob needs to be emptied in any case. Thanks again for the replies, I sure hope this works!

 

[extremetrek]

Okay, so since I cleaned the MAF (and yes it was dirty) and reset the KAM, the problems have continued. Crappy idle, crappy gas mileage, and sputtering and dieing (0-2000 rpm) at initial start up. I haven't gotten any more CEL, but the KOER self test still says System Lean/System ALWAYS Lean.

AS SOON as I unplug the MAF the car starts normally, idles fine etc...plug it back in and the system goes to S***. Is this definitive proof that the MAF is the problem and should be replaced, or could something else still be causing this? Thanks for the advice!


EDIT: QUICK ANSWERS APPRECIATED GETTING READY TO GO GET A REPLACEMENT VERY SOON!

 

[bill302]

i would say it was the maf or either the o2 sensors...

 

[bill302]

The MAF doesn't look bad to me at all...I have an oil seperator installed past the PCV and I am going to empty that and replace the PCV valve (who knows when that was done last). I'll look for info on checking the voltages off of the MAF...and whats a KAM and how do I reset it?

PS: Anyone know the size of the idle stop screw? I can't seem to adjust mine and it would be nice to rip it out and put in something that would work...thanks!

you can lightly tap the idle set screw on top with a hammer until it comes out thru bottom its pressed in but its easy to remove and go to the hardware store and buy a bolt and two nuts with washers and do as i did in the pics. below...

 

[extremetrek]

Hey thats exactly what I was looking for with the idle set screw...thanks!

I replaced the MAF...NO CHANGE, still runs better with the MAF unplugged...grrr so frustrating!

 

[mo_dingo]

I think Scott knows the thread size for installing a throttle stop screw. I just use needle nose pliers.
Good luck.

Yeah I used to but i can't recall it. I replaced the bolt after I started keeping a list of bolt sizes for our cars. I just backed the bolt all the way out and took it to the hardware store. I do remember it being metric and fine thread, something around M6.

Have you ran a cylinder balance test manually yet???? idk what the code 90 is all about, doesnt make any sense to me.
Scott

 

[extremetrek]

Code 90 on the cylinder balance test means that the system is functioning...today MORE fun!

Drove to work car starts overheating, pull over pop the hood and coolant is SHOOTING up from the heads (I think) gonna have to take a closer look at THAT when I get home. I fear a leaking head gasket or at best a leaking intake gasket where it meets the head. Is this the problem, or is my LEAN problem the cause of this?

Thanks for the help!

 

[extremetrek]

UPDATE

I think I found the coolant problem, most likely not a HG, which is GOOD news!

Like I said before, on cold starts the car will not run at all without a LOT of help from me...but I have learned that if I just shut the car off and turn it right back on again it runs, albeit with that lopey idle problem but at least it runs...is that TPS related...we checked voltage I think it was 1.04.

Secondarily, the fuel pump, I am begining to notice is loud I can hear it when its sitting and driving. The car seems to think its running lean which I guess a crappy fuel pump woud cause huh? Just replaced the fuel filter. Could it be fuel problems that are causing my idle problems? Doesn't turning the key to "on" prime the fuel system so theoretically when I start the second time the fuel pressure is built up better so the car runs better?

Thanks in advance for any help!