MAF sensor problem
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MAF sensor problem
Hey guys,
I have a 98 Ranger 4.0, 140K miles I recently got my lean codes back on both banks. A year ago I got these codes after installign a pre oiled fram pos filter. Cleaned MAF and was good for another year. Got the codes back a month ago. Cleaned it again and put in a paper filter. A month later got lean codes again, cleaned sensor and got the check engine light back a couple days later. The truck runs fine just at idle i can hear a irreguality. I unplugged the MAF and she ran better so is the sensor dead? Im doubting intake gaskets right now since she runs great. Also are the reman units for napa?
Thanks alot, Dave
I have a 98 Ranger 4.0, 140K miles I recently got my lean codes back on both banks. A year ago I got these codes after installign a pre oiled fram pos filter. Cleaned MAF and was good for another year. Got the codes back a month ago. Cleaned it again and put in a paper filter. A month later got lean codes again, cleaned sensor and got the check engine light back a couple days later. The truck runs fine just at idle i can hear a irreguality. I unplugged the MAF and she ran better so is the sensor dead? Im doubting intake gaskets right now since she runs great. Also are the reman units for napa?
Thanks alot, Dave
Post Fiend
Joined: Jan 2003
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From: Connecticut
It's hard to confirm a bad MAF without a scanner to tell you what's going on with it. The simple voltage tests aren't all that telling.
From what I have heard, the same company that remans MAFs for Napa also does it for the manufacturer.
Have you tried a propane "sniff test" around all the vacuum hoses and upper intake??
From what I have heard, the same company that remans MAFs for Napa also does it for the manufacturer.
Have you tried a propane "sniff test" around all the vacuum hoses and upper intake??
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No I haven't done the upper intake test test since its snowing here and i dont think its an actually air leak since she purrs, just at idle she sounds a lil funky/erratic but this stops when i disconnect the maf.
Yeah I haven't gotten any sensor codes just lean on both sides. I might just pickup a maf for 98$ at auto zone w/ a 1yr a warranty as i have emissions test coming up. Ill let you guys know of the result.
Yeah I haven't gotten any sensor codes just lean on both sides. I might just pickup a maf for 98$ at auto zone w/ a 1yr a warranty as i have emissions test coming up. Ill let you guys know of the result.
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Autozone pulled the same codes so I went ahead and replaced the MAF, took about 10 min and I disconnected the batt. It my dads car so it hasn't been driven yet but at idle it sounds the same 
. If the light comes back I would also like to know how to perform the sniff test and im wondering if I could use a mapp gas torch?
. If the light comes back I would also like to know how to perform the sniff test and im wondering if I could use a mapp gas torch?
Post Fiend
Joined: Jan 2003
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From: Connecticut
Yea, MAPP gas should work too, but the key is that you don't want to light the torch, you just want to feed a little unburnt gas through the nozzle and "sniff" the suspect areas all around the engine bay while the engine is running. If there is a vacuum leak somewhere, the unburnt gas will be drawn into the upper intake, thereby causing an increase in RPMs.
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From: Omaha, NE
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yeah thats what I thought, but its my dads car and he wanted to try the easiest thing first. At least hopefully its not the lower intake gaskets. If the codes come back looks like im going to have to tear into it..... At least theres a good guide thanks to this forum
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From: SW Va
I'd inspect all the vacuum lines & this would include the heater controls, vapor recovery lines, brake booster & the PCV valve & hoses. If the PCV valve is sticking open, it'll act as a unprogrammed for vacuum leak & mess with idle quality.
The propane sniffer is a good tool for spotting a vacuum leak.
If you need to get into some tight spaces, add a section of tubing, with a ports needle in the end, to fashion a fine tune probe, for locating & pinpointing a small leak.
If you decide to clean a MAF sensor, remove it & carefully clean with a non residual plastic safe clesner, or a formula that says it's recipe is for cleaning MAF sensors.
If you find it was dirty, then look up stream & find out why/how it got dirty!!!!
The propane sniffer is a good tool for spotting a vacuum leak.
If you need to get into some tight spaces, add a section of tubing, with a ports needle in the end, to fashion a fine tune probe, for locating & pinpointing a small leak.
If you decide to clean a MAF sensor, remove it & carefully clean with a non residual plastic safe clesner, or a formula that says it's recipe is for cleaning MAF sensors.
If you find it was dirty, then look up stream & find out why/how it got dirty!!!!
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From: Cypress, CA
Paw paw is right in that it takes little "dirt" to cause a MAF sensor to produce erronious readings. A good quality electrical cleaner seems to work well. Do not touch the wire with your fingers at all - just clean it with the aerosol and blow it dry with some compressed air. Reinstall the MAF and run it for a few miles - long enough for the computer to relearn the signals from the clean MAF. Have not actually had a MAF go completely bad in a very long time.
Hope this helps.
Russ
Hope this helps.
Russ
Post Fiend
Joined: Oct 2005
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From: Kiev, Ukraine
You may have vacuum leak. Usually dealers have MAF for tests, they check how much MAF reads on idling engine, swap MAF and check againe with scanner (reading OBD data/Actual values)....
My ranger had similar problem with cracked air intake....
My ranger had similar problem with cracked air intake....
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Yeah i installed a new maf and no go, got the codes back and cleared them. Sprayed all the hoses and as close as i could to the intake with carb cleaner and didnt find anything. I'm leaning towards intake gaskets because shes been using a lil coolant for a while now , but she runs great so maybe the gasket is a little outta shape, still got a little time before emissions testing. Since it performs great i don't thinkk its fuel related.... Ill try running a sniff test when I can.
How long and how hard do you think the upper and lower intake gaskets would be? And I heard it might be the fuel rail gasket also?
At idle it sounds like a reallllyyy slight miss when shes turned on then the comp i guess ups the idle and its fine its almost not noticeable but its setting off lean codes....
How long and how hard do you think the upper and lower intake gaskets would be? And I heard it might be the fuel rail gasket also?
At idle it sounds like a reallllyyy slight miss when shes turned on then the comp i guess ups the idle and its fine its almost not noticeable but its setting off lean codes....
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