Question for everybody(MAF)

Guys i wanna ask is somebody had a problems with MAF sensor, and how you check that, and what symptoms?

Another question, what wires and plugs best in autozone. And one more do i have to gap the plugs or just buy it and install it. 2003 imp,3.4eng,85000m

The best spark plug wires are the OEM GM stock ones.

I have never HAD to gap any spark pugs, but I do always check them. you can just buy a gap ckekcer at autozone, they are $.99.

Do you think it would be hard to remove these plugs at 100K miles or should I just spray PB Blaster or WD-40 on it to help me break these plugs free been wanting to change them but afraid they will be stuck to the heads ANY HELP???????

By the way i have a 2002 3.4L impala

no, dont spray anything in the plug holes, when you go to take out your plugs, that leaves a hole into your engine, and you dont want anything thats not supposed to be in your engine... in your engine.

No, I'm talking about before pulling the plugs. Otherwise how would I get these plugs out????? Don't forget these plugs do stay in the engine for 100,000 miles. Would it still be easy to take them out. Any tips to know about.

well, if you soak them in rust eater or something, how are you going to get the rust eater, out of the plug holes? you cant really shove a rag or anything in there to soak it up, trust me I tried on my old car, and I ended up having to let it sit overnight to let everything evaporate.

really the only thing you can do is try to take them out, and if they are stuck, well, I dont know, I have never had any plugs sieze into the heads.

Good point

WAIT what about using a hair dryer?

to dry up the rust eater of course.

Guys i wanna ask is somebody had a problems with MAF sensor, and how you check that, and what symptoms?

Normally a MAF sensor in bad shape will trigger a odb-ii DTC error code and a SES/CEL light. However, they have been known to give driveability problems without any codes too.

One symptom of a bad MAF is erratic or no idle. Engine will stall out or you have to hold the rpms up to prevent stall. May be accompanied by engine backfire or black smoke out the exhaust.

Another is similar to a clogged CAT where your acceleration will be poor or it will miss or cutout at 3K - 4K rpms. The effect will be felt when accelerating or WOT and while the PCM is in open loop mode.

A MAF sensor is hard to check. You can check the 5 volt reference signal from the PCM. The output back to the PCM is a frequency based signal proportional to airflow. To check it you really need an oscilloscope or a diagnostics program like AutoTap. Otherwise you're stuck with controlled substitution to rule it out as a problem.

Thank you Bnaylor3400 you really help me. I sent you before on private mesages. So looks like we check everithing and still this problem.
Alright one more thing, how i can check the coils?(how many ohms) Or maybe you can think something else?
Thank you again.

Another question where usually we have vaccum leak?

Guys i wanna ask is somebody had a problems with MAF sensor, and how you check that, and what symptoms?

Another question, what wires and plugs best in autozone. And one more do i have to gap the plugs or just buy it and install it. 2003 imp,3.4eng,85000m

On spark plugs use the oem AC-delco the book calls for.
If they hand you bosch or something else pitch them back and get the good AC.
Always check the gap because somebody could have droped them.
But beside checking the gap center the tip with the electrode.
I have found a lot of the off center. On the double platinum tips center the two platinum tips with each other. single platinum just center the tip with the electrode.
Hold your plug with a wrench and grab the tip with a pair of pliers and twist it to center the plug tips.
Also a little dab of anti-seize wll help someone else get them out the next time.
Skunk pee or penetrating oil will not help to break a plug lose. It is sealed where it screws into the head. If one screws out 3-4 threads and then gets real tight it might help or might not. Or just cross your fingers and hope it comes on out.
That is one good reason to change the plugs before 100k
Good luck
MT

Guys i wanna ask is somebody had a problems with MAF sensor, and how you check that, and what symptoms?

Another question, what wires and plugs best in autozone. And one more do i have to gap the plugs or just buy it and install it. 2003 imp,3.4eng,85000m

On the mas air flow sensor watch the baro readings and fuel trims in the computer.
If you need a chart E mail me at [email protected] for a pdf on it.
Or if private e mail will take a pdf try that.
MT

I dont understand what you saying about Maf sensor. Bnaylor3400 saying if maf was bad your rpm gonna drop, which i dont have. Maybe Maf is fine but take a look on this. I have everithing exept SES light.

A/T - Shift/Driveability Concerns/SES Lamp ON

Bulletin No.: 04-07-30-013A
Date: January 25, 2005
INFORMATION
Subject:
Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter
Models:
2005 and Prior GM Cars and Light Duty Trucks
2005 and Prior Saturn Models
Supercede:
This bulletin is being revised to add additional model years and to clarify warranty coverage. Please discard Corporate Bulletin Number 04-07-30-013 (Section 07 - Transmission/Transaxle).
http://www.alldatadiy.com/alldata/AFI~V6570537~C37398~R0~OB0~P3R0H~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/34856143/42063449/57413322/112163062/111809841/111818979
The use of an excessively/over-oiled aftermarket, reusable air filter may result in:
^Service Engine Soon (SES) Light On
^Transmission shift concerns, slipping and damaged clutch(es) or band(s)
^Engine driveability concerns, poor acceleration from a stop, limited engine RPM range
The oil that is used on these air filter elements (http://www.alldatadiy.com/alldata/AFI~V6570537~C37398~R0~OD~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/34872087) may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur.
When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern.
The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty.
If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs.
Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items.

I dont understand what you saying about Maf sensor. Bnaylor3400 saying if maf was bad your rpm gonna drop, which i dont have. Maybe Maf is fine but take a look on this. I have everithing exept SES light.

A/T - Shift/Driveability Concerns/SES Lamp ON

Bulletin No.: 04-07-30-013A
Date: January 25, 2005
INFORMATION
Subject:
Automatic Transmission Shift, Engine Driveability Concerns or Service Engine Soon (SES) Light On as a Result of the Use of an Excessively/Over-Oiled Aftermarket, Reusable Air Filter
Models:
2005 and Prior GM Cars and Light Duty Trucks
2005 and Prior Saturn Models
Supercede:
This bulletin is being revised to add additional model years and to clarify warranty coverage. Please discard Corporate Bulletin Number 04-07-30-013 (Section 07 - Transmission/Transaxle).
http://www.alldatadiy.com/alldata/AFI~V6570537~C37398~R0~OB0~P3R0H~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/34856143/42063449/57413322/112163062/111809841/111818979
The use of an excessively/over-oiled aftermarket, reusable air filter may result in:
^Service Engine Soon (SES) Light On
^Transmission shift concerns, slipping and damaged clutch(es) or band(s)
^Engine driveability concerns, poor acceleration from a stop, limited engine RPM range
The oil that is used on these air filter elements (http://www.alldatadiy.com/alldata/AFI~V6570537~C37398~R0~OD~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/34872087) may be transferred onto the Mass Air Flow (MAF) sensor causing contamination of the sensor. As a result, the Grams per Second (GPS) signal from the MAF may be low and any or all of the concerns listed above may occur.
When servicing a vehicle with any of these concerns, be sure to check for the presence of an aftermarket reusable, excessively/over-oiled air filter. The MAF, GPS reading should be compared to a like vehicle with an OEM air box and filter under the same driving conditions to verify the concern.
The use of an aftermarket reusable air filter DOES NOT void the vehicle's warranty.
If an aftermarket reusable air filter is used, technicians should inspect the MAF sensor element and the air induction hose for contamination of oil prior to making warranty repairs.
Transmission or engine driveability concerns (related to the MAF sensor being contaminated with oil) that are the result of the use of an aftermarket reusable, excessively/over-oiled air filter are not considered to be warrantable repair items.

If you do not have any symptoms of a bad MAF sensor, then your MAF sensor is probably OK. The above refers to using aftermarket oiled air filters like K&N drop in or cone filter like on a CAI/FWI.

Are you using an aftermarket oiled air filter? The MAF sensor can be cleaned with MAF sensor spray cleaner (Gunk brand) if you suspect contamination. The MAF sensor on a 3.4L is very easy to clean or replace.

First. Where i can get that maf cleaner.?
Second, i have hard shifting and major loss of power(and plus when accelerating noise looks like valves ticking). Ihave everithing like maf sensor bulletein saying exept SES light. (today was chaged another set of wires)

I am tired of spending money. Maybe you can think something else.
Thank you so much, looks like you have big expirence.

Another thing, how i can check coils?

First. Where i can get that maf cleaner.?
Second, i have hard shifting and major loss of power(and plus when accelerating noise looks like valves ticking). Ihave everithing like maf sensor bulletein saying exept SES light. (today was chaged another set of wires)

I am tired of spending money. Maybe you can think something else.
Thank you so much, looks like you have big expirence.

Another thing, how i can check coils?

I got my MAF cleaner from Autozone. Its in a gray can with the Gunk label.

If you have a mulitmeter you can check the resistance of the coil primaries and see if in spec. per the service manual. Also, under the coils is an Ignition Control Module (ICM). I've had the ICM tested at Autozone for free.

Thank you Bnaylor3400 i clean the MAF sensor and still the same thing, And plus today guys from strauss cleand my injectors thru the intake. So looks like i dont have mechanical problem. Probably electrical. About coils i mesured with ohms and kohms and it showed me 0. i dont know why there no resistance owethere.

Thank you Bnaylor3400 i clean the MAF sensor and still the same thing, And plus today guys from strauss cleand my injectors thru the intake. So looks like i dont have mechanical problem. Probably electrical. About coils i mesured with ohms and kohms and it showed me 0. i dont know why there no resistance owethere.

The proper values are in the respective GM service manual. Off the top of my head primary resistance is around 0 - 2 ohms. Secondary coil resistance around 5K - 8K ohms.

Didn't you mention earlier that you could hear the engine knocking or rattling like possibly pre-ignition or detonation? You are aware there are two knock sensors that feed knock data to the PCM module. If bad they should trigger a SES/CEL light but not always. One is located right by the oil filter on the side of the engine towards the radiator and the other on the back side of the engine block. The knock sensor(s) will retard ignition timing and reduce power when detonation is detected. Thats about all I can think of for now.

WAIT what about using a hair dryer?

WD 40 or rust eater dripping into the motor will not hurt anything.It may help you get the plugs out although they should come out with no problem.I put a little never-sieze on plugs when i put them in.People also use WD 40 as starting fluid on diesel engines.

Has the original poster in this thread checked for a clogged Catalytic Converter yet?... I had some of the symptoms he is describing until I finally had the CAT replaced... Now the car runs like a rocket!...

Has the original poster in this thread checked for a clogged Catalytic Converter yet?... I had some of the symptoms he is describing until I finally had the CAT replaced... Now the car runs like a rocket!...

I believe he has. Replaced with an aftermarket direct fit. He's had other posts on the same issue.

A new CAT does wonders if thats the problem. :bigthumb:

Hi bnaylor3400 i so pissed right now, i just from dealer he check this freaking car and saying everithing is ok, but i am not stupid tha car runs like crap. He sayd computer couldnt find nothing. I wanna ask you 2 questions , first about oil pressure how can i check that, cause maybe before i put syntetic and something wrong with pump, maybe on top not enough oil i mean loosing compression wich causing missfire. Because all this problem(loss of power, kickback upshifting and noise looks like valves) start when i start changing stuff. And another question what is firing order. I mean when you open the hood from left to right i have this coil location 5and2, 3and6, 1and4. Is this rigth just i case, maybe sombody before reverse it. Thank you so much guys.
I still cant belive those idiots charge me 113$ for diagnose and find nothing.
One more thing, satturday i had conversation with couple of mechanics, and he put his hand on exaust mufler pipe and gases dosent coming out smooth, and he sayd thats misfire and if no SES light then this problem is gonna be hard to find. He sayd method illumination. So if this method then look at this guys(was changed): CAT, fuel and air filter, plugs and wires two times, maf was cleaned, injectors was cleand 2 times, coils is fine (6,38-6,40 kohms),fuel pressure 52-54psi, sometimes having DTC P0420 but like forum saying(dont worry about it).
I dont know what else it could be, but i am really not happy with GM.

Hi bnaylor3400 i so pissed right now, i just from dealer he check this freaking car and saying everithing is ok, but i am not stupid tha car runs like crap. He sayd computer couldnt find nothing. I wanna ask you 2 questions , first about oil pressure how can i check that, cause maybe before i put syntetic and something wrong with pump, maybe on top not enough oil i mean loosing compression wich causing missfire. Because all this problem(loss of power, kickback upshifting and noise looks like valves) start when i start changing stuff. And another question what is firing order. I mean when you open the hood from left to right i have this coil location 5and2, 3and6, 1and4. Is this rigth just i case, maybe sombody before reverse it. Thank you so much guys.
I still cant belive those idiots charge me 113$ for diagnose and find nothing.
One more thing, satturday i had conversation with couple of mechanics, and he put his hand on exaust mufler pipe and gases dosent coming out smooth, and he sayd thats misfire and if no SES light then this problem is gonna be hard to find. He sayd method illumination. So if this method then look at this guys(was changed): CAT, fuel and air filter, plugs and wires two times, maf was cleaned, injectors was cleand 2 times, coils is fine (6,38-6,40 kohms),fuel pressure 52-54psi, sometimes having DTC P0420 but like forum saying(dont worry about it).
I dont know what else it could be, but i am really not happy with GM.

The coil pack order looks correct if you are looking at it from the front of the engine looking in.

If the oil pressure was not good you would have a Oil Warning Light. The sending unit is located by the oil filter. Unless you have an oil pressure gauge in the IP to check actual oil pressure you'd have install an aftermarket oil pressure gauge for troubleshooting purposes.

Have you considered running a compression check of all 6 cylinders. The gauge doesn't cost that much. If nothing is showing up at the dealer or on a Tech II the maybe you have an internal engine problem.

How i can check compression by my self, cause alldata showing whole history(you have to disconnect pcm bla bla bla). And where i can get gage. Maybe something wrong with the valves( not closing proberly). And plus its maybe you know what: i have direct fit cat (aftermarket) and metal is very thin, so you can hear all the noises. Thats another opinion. Look at this , this looks to me hard to check alone.
Testing and Inspection

Engine Compression Test
A compression pressure test of the engine cylinders determines the condition of the rings, the valves, and the head gasket.

Important: Remove the Powertrain Control Module (PCM) and the ignition fuses from the I/P fuse block.


Disable the ignition.
Disable the fuel systems.
Remove the spark plugs (http://www.alldatadiy.com/alldata/AFI~V6591338~C37398~R0~OD~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/58828691) from all the cylinders.
Remove the air duct from the throttle body.
Block the throttle plate in the open position.
Measure the engine compression, using the following procedure:6.1.Firmly install the compression gauge to the spark plug (http://www.alldatadiy.com/alldata/AFI~V6591338~C37398~R0~OD~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/58828691) hole.6.2.Have an assistant crank the engine through at least 4 compression strokes in the testing cylinder.6.3.Record the readings on the gauge at each stroke.6.4.Disconnect the gauge.6.5.Repeat the compression test for each cylinder.

Record the compression readings from ail of the cylinders. The lowest reading should not be less than 70 percent of the highest reading.
No cylinder reading should be less than 689 kPa (100 psi)
The following list contains examples of the possible measurements:
When the compression measurement is normal, the compression builds up quickly and evenly to the specified compression on each cylinder.
When the compression is low on the first stroke and tends to build up on the following strokes, but does not reach the normal compression, the piston rings may be the cause.
If the compression improves considerably with the addition of three squirts of oil, the piston rings may be the cause.
When the compression is low on the first stroke and does not build up in the following strokes. the valves may be the cause.
The addition of oil does not affect the compression, the valves may be the cause
When the compression is low on two adjacent cylinders, or coolant is present in the crankcase, the head gasket may be the cause.
Remove the block from the throttle plate.
Install the air duct to the throttle body.
Install the spark plugs (http://www.alldatadiy.com/alldata/AFI~V6591338~C37398~R0~OD~N/0/89012112/94694975/94694986/94694990/34853741/100411974/34853743/58828691).
Install the Powertrain Control Module (PCM) fuse
Install the ignition fuse to the I/P fuse block

How i can check compression by my self, cause alldata showing whole history(you have to disconnect pcm bla bla bla). And where i can get gage. Maybe something wrong with the valves( not closing proberly). And plus its maybe you know what: i have direct fit cat (aftermarket) and metal is very thin, so you can hear all the noises. Thats another opinion. Look at this , this looks to me hard to check alone.

You'll need a second person. One will have to hold the compression tester and the other will crank the engine over. The gauge is available at places like Autozone.

To disable the ignition you can pull the PCM fuse and to disable fuel system pull the fuel pump fuse.

Although it specifies nothing less than 100 psi good compression is typically around 125 - 140 psi on a 3.4L. Also all six spark plugs should be removed before running test.

Hi bnaylor3400 , so i never got a chance to check compression. And still think there is nothing wrong witn compression. Look what i just remember, when i got this car 7 mount ago, next couple of weeks i had (sometimes) hard starting and electrical burning smell, sure you gonna think (this is rubber smell and this is cat), but no this was electrical smell. And after maybe 2-3 weeks it finished. So maybe i have some electrical problem? I couldnt find anything, but smell was from driver side somewhere, from fuse box(deeper) or around PCM. There wasnt any SES. If you think i still have to check compression, wich i think i have sheety after market CAT with thin metal, so you can hear everething. So, brother i still have this hard shifting and feels like missire(cause engine i shaking(detonating)), but i wondering why i dont have SES light.
And another question i found on ALLDATA all solenoids(tranny) resistance wich i can check with tester thru the pins, what you think if it was something wrong solenoids it should throw me the code, right? So if no tranny code, then no tranny problem. And those dealers cant find anything cause they using that stupid tech2. What else you think can give missfire or hard shifting without SES light.
Cause guys on two reply down with "impala power" saying about spining tires, then i think i can make it smoke(when TRACTION OFF) so we 1 problem less, iam about low power.
Any info thankfull.

I'm just about all out of suggestions. On the tranny I would assume a code would be triggered. Some tranny error codes do not generate a SES light but a good scanner should pick up any possible stored codes.

If you noticed a smell of burnt electrical or wiring I would do a closer inspection. Especially the wiring harness going to the PCM module and the Ignition Control Module. There are two wires, red and orange which supply 12 volts to the PCM from the battery and ignition control circuits. I've seen these wires damaged from a simple jump start or bad charging system problem. Also, in the same wiring harness and to the PCM 80 pin connector I'd check the lines for the ignition control module Bypass and PC mode operation. If stuck in bypass it will give misfires, however, an error code of P300 along with P1361 & 1362 are normally stored.

Other than that :dunno: