MAF sensor on a 2001 Impala 3.8l

[Im Lon 2]

I have been having an issue with the car surging at 55-60 MPH when I would let off the Gas. Yesterday it started doing it at any speed and the check engine light finally came on so I could test out the Codes. The code came up as P0102. But when the guy was testing it he said it sounds like a vacuum leak. Last night we took apart the Air Filter box, and the boot that connects the filter box to the Throttle body. The Sounds sounds like it is coming from the Throttle body itself. I have checked all the air lines and cannot find anything wrong with any of them. Does anyone know what this noise could be caused by? Maybe one hose is clogged?
Also have 2 other questions regarding Sensors. there are 2 sensors I'm not sure of... 1 is on the boot that connects the Air filter to the throttle body. And 1 on the throttle body.. What are these 2 sensors called. one I'm guessing is the MAF but not really sure.

Any Suggestion would be appreciated
Lonnie

[maxwedge]

One in the duct is the int. air temp sensor and the other is the maf. You may have a bad throttle body gasket for the vacuum leak, also anyone replace pcv recently?

[Im Lon 2]

I was also told by a friend a little bit ago that it could have something to due with the throttle sticking? One of the problems I noticed last night explains why when I step on the gas that it sticks (in the morning, or after the car has sat for a while.) When we had the Car apart last night we noticed that the throttle is gummed up inside the throttle body, causing the throttle to stick.

My buddy said the MAF should be the last thing to replace because it is probably a problem before the MAF, but the MAF is catching the problem and sending a signal to the Engine light not necessarily it being the MAF itself even though it is what is throwing the code.

Before I spend 150. on a sensor (the size of a soda cap) I'm going to clean the Throttle body with some throttle body cleaner, then put everything back together and test it again. He also said to take the Throttle body cleaner and spray it around the air lines if the engines idol increases you can find the leak vacuum leak if there is one.

Where is the Throttle Gasket located?

Yes I just replaced the PVC valve last weekend. Before the problem got to where it is today.

[maxwedge]

1st do not use TB cleaner on the maf, use specific maf cleaner made by CRC. Second, make sure both o rings are in place in the pcv, there is one just under the map and a smaller one the pcv goes into. TB seal/gasket is where the TB mounts to the intake.

[Im Lon 2]

I took off the Throttle body (which was loose), and replaced the Throttle Body gasket, cleaned out out the throttle body with Throttle body cleaner, and a tooth brush.. Looked like new when I put it back together. So far it sounds and seems to be running smooth.

thanks for the help.

[mattridessleds]

I have the same problem with my 2000 impala 3.8l. I replaced the connector to the maf sensor at first because it was only sending a reading occasionally to the computer. Check engine light was off for a month. Came back on, the new connector wansn't making contact with the 3 pins inside the sensor itself. So i bought a remaufactured sensor. This fixed the problem for another month. light comes back on. figured because i cheaped out and bought the remanufactured sensor it went bad. So i went to the junk yard and bought one off a junker. Same problem. New connector again-same problem. I thought it may have been a vacum leak as well. Replaced the plenum with a new one because i had coolant leaking out from around the sides and had a whistling sound coming from somewhere. New plenum and intake gasket (while i was at it) and same problemo. The po102 code.

[Im Lon 2]

Well, just like others I have read.. Works great for a couple of days and then right back at it. I don't get it. I just got some MAF cleaner and seems to be running good again. But I don't feel comfortable about it at all.

Just curious could a plug be fouled and just throwing the car off? I bought new plugs, and wires but have not had a chance to change them out.

I'm getting really close to take it to the dealer, but god knows they are going to change everything like I'm doing now till they find a problem.

Once again I have no clue

[maxwedge]

Sit on it and see if the code comes back if it does the maf just may be bad a full scan would show that and again was the pcv replaced? Remember the 2 o rings that are sealing the pcv, if one is left out you can set that code. I asked you that, no answer?

[Im Lon 2]

The PCV had both Seals when I put it on. It has a spring that sits below the PCV and the top fit on pretty snug, was king of hard to put everything back together. I have only gotten P0102 code one time, that is what has me so focused on these type of problems.. I'm wondering now if there is a different problem in general.

Yesterday, my belt started squealing, and caused the car to die, 2 different times? The car has never died on me, till then. The belt was replaced Oct 06, and still looks New.

Is there anything else that could cause the Car to surge, with out sending a code to the check engine light? Plugs? Fuel Filter?

I'm changing out the plugs this weekend. The car has 111,xxx miles on it and the Plugs/Wires have never be replaced.. We have never had a major problems with the car till a month ago.

[SpinnerCee]

Seems like the cat has failed/is failing -- An exhaust back pressure test will tell you for sure -- this an extended emissions warranty repair at the dealer.

[Im Lon 2]

I have also thought about something else.

About a month ago before this problem started, I forgot my wallet at home when my fuel light came on. I had to drive all the way back home from work about 60 miles after the light came on. I wonder if the fuel filter could be clogged a little, causing not enough fuel, and then with to much air, if that could have set off the MAF sensor a week ago?

Any thoughts?

[Im Lon 2]

replaced the MAF and everything is running fine. No codes

Thanks for everyones help!

[Im Lon 2]

Originally Posted by maxwedge

and again was the pcv replaced? Remember the 2 o rings that are sealing the pcv, if one is left out you can set that code. I asked you that, no answer?

Thought my belt or something was giving off this ear piercing squeal. I wish I would have paid more attn to this comment. Took out the PCV last night no O-ring.. Put in a new O-ring, Vacuum sound gone, squealing sound gone, and the Car runs much better. $500 later for a .39 cent O-ring. But hey... Got some new parts

[mattridessleds]

After replacing this sensor twice with no luck I am wondering if the sensors are manufactured for specific vin#'s. I've tried the re-manufactured ones and also one off a junker.

[SpinnerCee]

@mattridessleds:

Maybe the MAF is not the source of your problem. Many "symptoms" as described will often have more than one solution/cause.

That's why we share our experiences here.