With the price of fuel to tow your boat (or for any other vehicle for that matter), do you ever clean your MAF sensor? This sensor, located in your engine's air intake, normally consists of either one or two tiny, fragile wires, or a plate. It senses the volume of air entering the engine, and the engine's computer uses the signal to control air/fuel mixture. The sensor gets dirty over time, causing the signal to become inaccurate. The result is often a too-rich mixture, reduced power, pinging, or a combination of all three.

Any decent shop can do this, but I'd bet they charge $100 for it. On many cars you can do it yourself with a screwdriver, a T20 security Torx bit, and a can of this:



A can of it is ~$7.00US at a common auto parts store. According to the MSDS', this product contains the same active ingredient (hexane) as CRC's QD Electronics Cleaner, but the MAF sensor cleaner has a higher percentage of it.

Mine is over 10 years old and had never been cleaned. It was obviously way overdue, and I was also due for a new air filter. It makes sense to do one job at the same time as the other. I've noticed in the past couple of months that my truck seemed to have a tad less power than normal and was pinging under load now and then. We'll see if this improves things. Total time for this job was about 30 minutes. Now that I've done it once, it won't take more than 15 next time.

Specific instructions on accessing the sensor on your make & year vehicle can probably be found with nothing more than a Google search.

Here's my sensor before cleaning:



And after. You have to look closely, but it's quite a difference:

I can't say I've ever cleaned it. I have had to replace the one on the Corvette twice, so I'm not exactly willing to mess it up and have to replace it again. Not cheap at $300 a pop.

What's making them fail?

Its a Corvette thing. Especially of my vintage. Code 33 & 34. I haven't had to replace it in 3 years, knock on wood. The cars also eat alternators. Just little quirks.

K&N air filters.

If you run a stock filter and change it when it gets dirty, you won't need to clean your MAF sensor.

K&N air filters are almost completely worthless....a stock engine can't use the extra airflow a drop-in K&N provides, and once just a little dirt gets trapped in it, the K&N's slight flow advantage is gone.
Plus, they pass FAR more dirt through them than a stock filter.

Pretty much all manufacturers have TSB's on problems caused by K&N filters. Usually from getting the MAF or IAT sensors dirty.

It's easy to do, but very unlikely the OP will see any benefit to the cleaning. I've seen them FAR dirtier than that.

Link to air filter test

From a friend of mine, his (from the mid 90's) are hard on distributors, which are tucked nicely BEHIND the harmonic balancer on the front of the engine block(nighmare to change).

Funny you should mention that. My experience has been just the opposite. Around the same time I changed to the current MAF, I went to a K&N filter. Haven't had any problems since, knock on wood. Plus I think it may have given me a few .01 in the eighth.

Let us know if cleaning the MAF makes a difference on fuel consumption.

Mark

I will. Just driving around town this evening I can say without a doubt that it's idling a little smoother. That's about all I can say definitively for now, but I'll report back.

I give the one in the Excursion a spray with contact cleaner during every oil change. It's a well known little "trick" on the Fords that fixes some idling and running issues for real cheap.

Funny thing, I just went thru this with my 1996 Lincoln, the day I picked up Bruce's transom door from Ryan...

Before leaving his shop, I remembered how my car had been running, and asked him if I could borrow his fuel pressure tester...

"Why?" - Because for a year or so, my car has been acting like it's starving for fuel when I get on it...

"What's it do exactly?" - It seems to run fine unless I stomp it. And when it's cold, it'll barely get past 2500 rpm sometimes. I changed the fuel filter but that didn't help, so I'm thinking maybe my fuel pump is going south...

"It's a Ford. ( ) Grab a screwdriver and pull out your MAF sensor."

I got the sensor out, and Ryan disassembled it just like Mike did. It also looked just like Mike's did.

By the way, this car gets a clean, factory style air cleaner regularly...

He sprayed the daylights out of it with MAF cleaner (AND--he specifically told me DO NOT EVER SPRAY A MAF SENSOR WITH CARB CLEANER, use ONLY MAF sensor cleaner!), then thoroughly dried it with an air hose...

Put it back together, got it in, I thanked him and took off, hoping to see at least SOME improvement...

Road's clear, I stomp it---and for the first time in MONTHS, the car stuck me in the seat, hitting 6500 and shifting into second with nary a blip! I seriously could not believe the difference!

--on a non-boating related note about this, another problem the car had for awhile, is that the torque converter wouldn't lock up. Didn't know why, but the trans otherwise worked fine. I just figured something was wrong with it. But immediately after the MAF cleaning (and still), the converter started locking up again! I have NO clue why the 2 are tied together, or why I never got a trouble code? (anyone?)...

Prior to the MAF cleaning, my on-board 'puter showed my average MPG at 17.6 (about a year's worth)... I reset it that night, and after a thousand or so miles, my average is 23.3, which is right where it used to be. Pretty substantial improvement!

FWIW, Ryan told me he's never had to replace anyones MAF. Just cleans them and they work fine...

This isn't much of a data sample, but I'll start with this.

My overall 15 month average MPG prior to cleaning the sensor was 13.85. That average is skewed a bit by towing, but not that much (especially last season ). That's quite a drop from the average during the first two years of the truck's life, when it was running in the low 17's.

In the first 100 miles since the cleaning, virtually all in-town stop & go driving, I got 16.03 - over 2mpg better, if the average holds. If anything, the average should be even better, as this first 100 miles had almost no highway driving in it.

The first tow of the season was yesterday, around 140 miles, at an average of 9.10mpg. As bad as that is, it's better than the 7-something I was getting before.

The truck is definitely idling much smoother, pinging under load has nearly disappeared, and the truck just seems slightly more "solid" out of the hole.

I'll update again when a more meaningful sample is available.

Any time you can get ANY improvement from something as simple a a spray or 2 from a can it's a good thing!!

Hmmmm, If my 'Burb' has one, I'll have to add this to my pull and clean/spray my PCV until it rattles freely again trick....

I would suspect K&N's affect (if any) on the MAF might be more from the filtercharger oil contaminating the MAF than dirty air getting through...But I have no facts here. I do have a K&N in the Jag FWIW....and am planning a whole K&N air intake kit on the 'burb', when funds align...

Yeah, while I don't use K&N on anything, there's nothing evil about them per se - it's the oil used on them and any other oiled filter that's the culprit with the MAF sensors.

Most people don't read the instructions which tell you to use very little oil and let dry for several hours before use.

Are MAP systems still used or are most vehicles now using MAF systems?

I'm pretty sure my truck has both.

My truck has a MAP system....and people wonder why my Hemi gets 13 MPG, while my brothers '04 F150 will get 17-18 with a 5.4....

??

MAP is techonlogy from the 70s...yet that is what Chrysler still uses.

Well, yeah, it's that, plus the fact that K&N's pass FAR more dirt through them than a factory filter does...plus, once they trap a small amount of dirt, they don't flow any better so that small advantage is gone, too.
Good air filter test
Another one
Quote from the second link:


No, thanks. I'll stick with a factory filter.

I missed this thread somehow, and a good one it is. I have a lot to add on this subject, but not tonite. Stay tuned.

I am on pins and needles!

I'm pretty sure even a MAF system uses a MAP signal.

One thing that gets overlooked is Oxygen sensors, they can cause excessive fuel consumption also, they should be replaced about 80,000 miles I think.

I've thought about replacing my O2 sensors, but 4 of 'em are spendy!

First off, don't arbitrarily (sp?) replace 02 sensors on 96 and newer vehicles - the systems are very sensitive and the computer will flag a lazy or faulty 02 sensor and set a code, unlike years ago where replacing an 02 sensor on a high mileage engine would yield a notable fuel mileage increases or better driveability.

Rear 02 sensor(s) (aft of a catalytic converter of course) job is only to be a tattletale on the converter's efficiency and are not used in adjusting air/fuel ratios. The