scully, i have always used brake kleen or a noncorrosive electronic cleaner to spary on maf wires. (do not use carb cleaner) Personally, i would never touch the wires (qtips included) as the filaments are too fragile and will easily break. Good luck.


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Hello, I cleaned the MAF sensors (2 thin wires) with CRC electric parts cleaners. The spray from the can goes far enough and with sufficient pressure to clean the sensors without touching them. The two sensors are shining brite now. I was also able to clean with the spray another sensor that is inside the MAF but further back in. Not sure what that is.

Am using a K&N filter that I keep clean. Tomorrow I will check the PCV valve and associated connectors. I will also take a look at the fuel filter. It may be partially plugged.

Thanks...

 

SCALF150,

Did you clean the MAFS 2 times ?

You posted that you cleaned it with Q-Tips on 04-16-2003 at 10:19 PM, and had reset the computer.

This post almost looks like you cleaned it a second time ??

If you did clean it a second time, did you reset the computer again after the 2nd cleaning ?

With the K&N filter, if you even do a slight over oil, it can coat the wires on the MAFS, and cause this problem.

Did you recently do a filter service to the K&N filter within say the last 30 to 60 days ?

 

I think the first time he cleaned it he cleaned the barrel and not the wires, this time it sounds like he cleaned the wires. That's my guess anyway.

 

Hello, I cleaned the MAF's two sensors the first time with the Q-Tip and reseted the computer. The CEL light went out for a few hours and then back on.

Then I cleaned the MAF's two sensors again, but this time with electrical cleaner spray. The spray does a thorough job and it doesn't touch the two sensors. I reseted the computer again. The CEL light went out for a few hours again but it came back up.

It has been more than 60 days since I last cleaned the K&N filter. I was planning on buying a regular filter and installing it while I clean the K&N filter. I have been using the K&N filter for over a year with no problems. Although the rubber gasket on the inside of it has lost most of its glue and it's kind of loose. I did clean a lot of oil residue form inside the filter housing.

 

Hi guys.

I want to thank you for the expertise I have readon this site. I have been reading off and on for about a year now, and finally decided to start posting. I have a '97 third door 4x4 w/a 4.6 that I inherited from my father. I had to trade the '01 F-150 in yesterday to please the wife, so I am sad. That is enough about me for now.

Thanks for the tip on the MAFS. I have had a CEL on now since I got the truck in Sept last year. I have since swapped the front two O2 sensors, and put the K&N in. I did this so I could put a Superchip in (which I have not gotten the time to make it work yet) and still get the CEL. I am going to get a code on it if the MAF and the PCV (which I am sure needs replaced anyway) updates a shot. If there is any more ideas, please keep them coming...

Again, thanks and keep up the help. Us novice mechanics need it...

Cheers

 

My 99 F-150 w/ 4.6L did the same thing you guys are talking about awhile back. I checked the gas cap and the MAF and they were all ok. I went to the dealership and they said the O2 sensor would have to be replaced ($250). I said no way and about 3 days later the CEL turned off and I havent had a problem since. Might want to just give it a few days.

 

The light would only turn off if the problem no longer exisits for 3 consecutive warmup cycles after a problem is detected. In your case you lucked out and the problem was no longer detected. However this is usually not the case, and something normally would need to be corrected for the light to go out, usually just depends on what caused the light to come on in the first place. As for my problem it had to have been the MAF as after cleaning it the light has remained off for over 400 miles now. Every problem is different, and it sounds like you may have gotten lucky.

 

I found the problem with the CEL on my F150. It turned out that the PCV hose assembly had a hole on the L-shaped rubber connector that attaches to the engine manifold. It was hard to find as the L-shaped rubber connector is all the way in the back of the engine. Impossible to visually inspect it. I had to feel and touch with my fingers the PCV hose assembly all the way back to the connection on the back of the manifold. Replaced with new PCV hose assembly for $28. No CEL light since replaced the PCV assembly.

I took advantage of the CEL situation and replaced the fuel filter as well. I suppose that after 142,000 it is good practice to replace some engine components. Especially, the ones made with rubber.

Anyway, thank all for your support.