Car acting funny, P0102 code
 

Ok, so the middle of 2010 my MAF sensor went bad and I replaced it. Now, my car has been running very oddly, and similar to how it ran when the MAF sensor went bad the first time. Hard crank, sometimes dying while driving, sometimes a very serious stutter in the engine while running.

Took it and had the code read, and a P0102 code came up. MAF Circuit Low Input.

How likely is it that the MAF sensor could have gone bad again so quickly? I'm going to go check the connection and make sure the wires are good, clean it up real good, and make sure my CAI isn't leaking near the MAF.

Is my failing UIM/LIM at fault for this at all or no? Any other possible fixes?

Just because it is new, does not exempt it from early failure.

Does your air filter require oil? Oil from an air filter can cause issues with MAF's.

Haven't oiled the filter since it's been put on in 2010.

Might have found it. Lets hope. The rubber boot connecting the engine to the CAI tube was loose, looks to be allowing air in/out in a weird. Gonna tighten it down and see what happens.

Usually when a MAF is cleaned, results can be pretty noticeable. But, if the symptoms still persist, then its either going to be a bad MAF, or a vacuum leak downstream of the sensor.

It is possible to test a MAF sensor in car, but results won't be as good as watching the g/ps on a scantool.

I don't have a scantool, nor do I have the money for one. :(

Wires look good. Tightening the boot around the CAI didn't help, the code just reset itself.

I'll have to head to O'Reilly or whomever and pick up some security torx and a can of MAF cleaner. See what happens then.

I don't hear any vacuum leaks, but I can check things you tell me to check.

Did you say the code went away? As in, the CEL went out? That seems to be an intermittent issue. But, it seems to quick. See, when a sensor sets of the CEL, that particular sensor has to fail X number of times before it will set it off. Then, the PCM needs to see it working X number of times before the light will clear out. Each sensor is different.
Some sensors will fail once and set the light off. Others, more.

To test for vacuum leaks around the intake/UIM/LIM area, just spray carb cleaner around the sealing areas while the engine is running. If the engine rpm changes, you found a vac leak.

Here is a link that shows how to test your MAF if you have a multimeter, if you have one that can read hertz then that is even better.

http://easyautodiagnostics.com/gm_ma...tic_test_1.php


If you have a laptop and about 30.00 I could help ya find a cheap way to allow checking/clearing codes, you'd use along with a ELM327 Bluetooth dongle, you would be able to read codes, and clear codes, as well as log some data.
The ELM327 is not the fastest IC from what I've learned, but it will be fastest enough for your needs, if you know how to work on circuit boards then you could swap out the ELM327 for the better/faster STN1110 IC, it is a little over my skill level personally, so I just use the ELM 327 that I got here, it is on sale for around 20.00 now.

Wait, forgot if you do have a laptop with a USB port then you can save a few bucks and get the wired ELM327

Both actually come with a few basic free programs, they work, but have no fancy GUI's, not that those are necessary.. :D

Awesome. Thanks for the links. I don't have a multimeter, but I plan on picking one up.

O'Reilly cleared the code for me when they read it, but it came back as soon as I started the car back up once I got home. It stayed for the drive home though. I need to pick up some security torx bits to pull the MAF out and look at it/clean it. I'm gonna be pissed if I look at it and there are some broken wires.

You're very welcome MouSe, hope ya get it figured out soon!

Ok my meter doesn't read Hz, so I just set it to volts. I found on a site that 2.5 is the normal reading at idle, and that it should change. I got the 2.5 but no change. Is this a correct test? If so it would seem my MAF is bad.

I just went out and tried that test on mine. At idle, it showed 2.62 volts. If I goosed it, it went to 2.61 volts. Hight rpm vs low rpm no change.

Well poop. What else can I do? I cleaned the sensor and had them clear the code. I figure if it comes back ill change the sensor

Sorry about that MoUse, I accidentally copied the wrong page, that was not for the 3.8L, to test the functionality of the MAF you need to be able to measure for hertz. :/
You can test for voltage and ground though.
http://easyautodiagnostics.com/gm_ma...gm_tests_1.php

Cheapest multi-meter I seen that will work is this, there may be others, but this is recommended on the article.


I do know how you should be able to get an idea if the MAF is functioning properly, go to an auto parts store that scans for codes, ask them to scan for codes for you, and while they are at it ask them if you can see what your MAF readings are on it, in like 2 clicks they should be able to have that info up, you won't see the hertz it is operating at, but if you goose it a bit you should see it change its g/ps readings.
At idle make a note of the readings, my MAF was bad, and it would only be a tiny bit off, nonetheless it was dipping low enough to start giving a cylinder 1 misfire code, it never gave a MAF code though, which was odd.

More than likely, they only use the pocket scanner(which won't see live engine data)

I thought some of them have decent model ones, the last store I went to had one that looked like mine, I have an Actron CP9575, maybe it was actually an older model..

Yeah, around here they only have pocket scanners.

I'd have to go to a mechanic and pay for a diagnostic for that.

You can drive up to NY and use my laptop.

he doesnt like the cold.

He doesn't like the cold, I don't like the heat. Guess he's screwed either way.

The MAF was bad. Replaced the sensor and the code went away.

Geez, you coulda told me you were going to replace it. I'm in Georgia right now on my way to you with laptop.

Oops, sorry.

You can still crash at my house.

Sweet, glad ya got it fixed!

I found the MAF sensor is really sensitive, when I had MAF issues like I said I never got a code, but my MAF was bad enough to give me a misfire, and cause me to run really lean (10-16 STFT & 16-20 LTFT at idle), and it was only off of what it should have been at idle by around .10 to .15 lb/m it was reading .43 to around .50 lb/mat idle, when around .65 at idle was more of where it should have been.

I know many say K&N oiled air filters are fine to use, but after spending 160.00 for a new MAF I'm not putting a K&N air filter back in there, as I have been told by some that tune cars for a living that the filters are bad for cars with MAF's, and I believe them.
I read that when your MAF mainly is effected is when humid, or humid+raining, as that helps the oil get to the MAF's thermistors, as to how true that is I cannot say, I just know I'll stick to the best non oiled filters I can find from now on.

Sorry, meant to mention of course CAI intakes don't have the filter that close to the MAF, so they are said to not be effected as much, I still don't trust the K&N oiled air filters anymore..
I figure better safe than sorry/out of another 160.00

ive put k&n drop in's in every vehicle ive owned, there have been quite a few. the only time i ever replaced a maf was because way back when my firebird still had the mpfi 2.8 i changed the ducting so it got the air from the bottom of the car with an elbow sort of like ram air. the first time i drove it in the rain it sucked up moisture and took out the maf. so its not the k&n or the oil, if you leave the stock ducting alone so you cant get moisture in there and dont go crazy with the oil it will be fine

I did use the filter for a few years before having problems, and I did clean it to no avail, it was still bad, so it is possible the MAF just was on its last leg already, I'm sure the thermistors do not have an infinite life expectancy, so it may have not been the oil on the filter.
I mainly choose to not put mine back in because right now if have another MAF fail I am screwed, as I am around 500.00 in the whole from car repairs already.

I do not have a CAI, but I did take my air-box out and gut the back side of it, I left the part past the filter/in between filter and MAF as it was stock, because I am pretty sure that along with the MAF screen help to keep the airflow straightened as if flows over the MAF's thermistors.


I admit I may have over-oiled it once or twice, back then I did not know MAF's could get contaminated with the oil if you overdo it, and I never cleaned the MAF because I did not know you are supposed to, so it could have partially been user error.

I may give the filter a try again in the future, I did not throw it away, I put it up in case I ever changed my mind, I paid too much for it to just toss it..

@ mouse so this is the car you wanted to trade me for the truck . sounds like a bad maf

Hehe yeah it is.

The MAF was bad. Replaced with a brand new one, not a REMAN like what was in there. Lifetime warranty this time!

I have had a terrible time with remans. I put 4 on one car at work in one day that were remans. some were causing a rich condition and some were causing a lean condition. These were all AC Delco remans. On the 5th try i replaced it with a NEW one and it was good to go. I know i will never go with a reman on my personal vehicle. Anyways glad you got it fixed.

:thumbup2

I only have had to replace mine once, but my overall experience with any re-manufactured sensors, or non-oe sensors has led me to always spend a little more to get an original new oe replacement if I can find it, it saves you the trouble of having to possibly buy another sensor.

Mine wasn't an OE Delco sensor, but some other brand. Probably made in China. Don't really care with the LTW though. RECEIPTS!