1999 Ford Explorer error codes

1999 FORD EXPLORER
149,000 MILES • 4.0L • V6 • 4WD • AUTOMATIC
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LALFAN1960
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i have a 99 explorer that i put plugs and wires on. had an issue on start up with a tube going into air intake tube that was off and didnt realize it. got some codes in it for running lean. found the tube and hooked it up and it ran pretty good. a little rough on start up. cleared the codes and now i got codes p1157, 1137, 1000, 1151 that came back up. not sure if i have another leak or why these codes came up again. didnt have codes prior to doing the plugs. i have looked up some and its 02 sensor not switching or is slow. i have a genisys evo to use for codes. thanks
Mar 7, 2015 at 10:52 AM
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ASEMASTER6371
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on your scan tool, what are the long term trims???

Roy
Mar 7, 2015 at 11:49 AM
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LALFAN1960
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Long term ft bank 1 22.0% bank 2 21.0% at idle on the datastream
Mar 7, 2015 at 11:54 AM
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ASEMASTER6371
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ok,there lies the issue.

I am sure you should have or will show 171,174 codes soon. these come from many possibilities.
vacuum leak in the intake system
pcv valve bad, stuck open
mass air flow failed. cleaning has little or no effect.
low fuel pressure

the codes for the O2 sensors may be coming from the fact that they cannot control the fuel/air ratio with the trims so far out

Roy
Mar 7, 2015 at 12:03 PM
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LALFAN1960
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OK. I had clear codes and tried driving about 10 miles and no codes yet. What should it be running and the rear 02 sensors don't switch unless u give it dome ROMs or is that normal. Thanks
Mar 7, 2015 at 12:11 PM
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ASEMASTER6371
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ok, clearing codes does nothing. that is only done after the issue is found, repaired and the very last thing is to clear them. there is freeze frame info you erased that could have helped us here in determining the failure.

the lean codes will not re appear for a while possibly a day or so.

the rear O2 should be relatively constant. the only job rear O2 sensors have is to moinitor the cat converter. they will not effect the running of the car.

Roy
Mar 7, 2015 at 12:14 PM
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LALFAN1960
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the codes before just came up on a test drive from an alighnment job. so figure in that much time they would have been back
Mar 7, 2015 at 12:17 PM
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ASEMASTER6371
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you will have to wait and see. once they come back, do not clear anything. use your scan tool and look at the freeze frame data.

Roy
Mar 7, 2015 at 12:19 PM
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LALFAN1960
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ok iwill try to find that if it comes back on. what will i need to be looking for?and far as the maf what kind of test is there for that if i can do it. thanks
Mar 7, 2015 at 12:26 PM
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ASEMASTER6371
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right now, lets look for the codes. the freeze frame ill give the reading at the time the code set. check the other items firat including the fuel pressure

Roy
Mar 7, 2015 at 12:29 PM
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LALFAN1960
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Trying get PVC out. So what about the Maf what do I need to do with it to check it?
Mar 7, 2015 at 12:34 PM
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ASEMASTER6371
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ok, what is the fuel pressure????

look for the voltage on the mass air flow at idle. when you rev the motor, it should change according to load.

did you do the other test as I suggested???

Mar 7, 2015 at 12:50 PM
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LALFAN1960
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Will have to rent a tester for fuel n figure that one out. Guessing they have a port on top for that. Going to put in new pcv. Was looking at Mac to see if it was dirty. What psi should fuel be
Mar 7, 2015 at 12:59 PM
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LALFAN1960
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Maf volts at idle .61 and rev it went to 1.94
Mar 7, 2015 at 1:06 PM
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LALFAN1960
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Light is back on. Codes p0171. 0174. 1000
Mar 7, 2015 at 1:09 PM
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ASEMASTER6371
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sounds like mass air flow is working at this point but the freeze frame will confirm.

yes there is a port. it should be around 45 lbs

you dont need to replace the pcv unless it is stuck open. check it first before replacing it.

vacuum leaks are real common issues with these motors. intake gaskets are common failures.

Roy
Mar 7, 2015 at 1:10 PM
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LALFAN1960
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OK when I'm on data stream I can freeze it. Is that what u want. And what am I trying to look for
Mar 7, 2015 at 1:15 PM
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ASEMASTER6371
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no, when a code is set by the computer, the pcm takes a snap shot of all the readings and saves them to a file. that will not happen until a code has been set

Roy
Mar 7, 2015 at 1:17 PM
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LALFAN1960
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OK. I have 3 codes with the light on. So what do I need to try. Sorry I'm an old car guy. Went to school in 79-80
Mar 7, 2015 at 1:28 PM
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ASEMASTER6371
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ok, look for freeze frame data in the codes menu. I need that info

what codes????

Roy
Mar 7, 2015 at 1:32 PM
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LALFAN1960
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Guess I sent them n didn't go thru or something. P0171. 0174. 1000. I hope I can find the info u want. Not real hood on the scanner yet
Mar 7, 2015 at 1:37 PM
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ASEMASTER6371
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the171,174 are the codes I new would come back

forget about the 1000. it was trying to run a monitor and was interupted.

Roy
Mar 7, 2015 at 1:39 PM
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LALFAN1960
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I'm not sure where to go to get your info. Scanner has all systemdtc scan. Automated test. Diagnostic trouble codes. Data stream. Custom data stream. Special tests. Not sure where to go for what u want
Mar 7, 2015 at 1:46 PM
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ASEMASTER6371
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open each menu one at a time and look at the possibilities. I have not used your scan tool so I cannot help you find it without being there

Roy
Mar 7, 2015 at 1:49 PM
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LALFAN1960
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Guess I will have to get back to u when I find out. Guess I can still try fuel pressure if you need it. Thanks
Mar 7, 2015 at 2:12 PM
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LALFAN1960
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what all info is on this if i can ever get it figured out. thanks. sorry about this
Mar 7, 2015 at 2:42 PM
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ASEMASTER6371
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it will gve trim percentage, tps, mass air flow, O2 sensor voltages, coolant temp among the top few
Mar 7, 2015 at 2:53 PM
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LALFAN1960
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So can I do that on live data. Shows all that02 sensor voltage or rich or lean. Shows something for tps. Has % for a lot of things
Mar 7, 2015 at 2:59 PM
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ASEMASTER6371
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You cannot show me the exact readings at the time the code set. That's what I need to see what triggered the code

Roy
Mar 7, 2015 at 3:01 PM
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LALFAN1960
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OK. Got u. I will try to see if this thing even does that. Don't think so
Mar 7, 2015 at 3:04 PM
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LALFAN1960
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Roy I finally got figured out the freeze frame of when the light was set. Doesn't give slot of info. Long term bank 1 was 18.8% long term bank 2 was 17.2% short term bank 1 was 7.0% short term bank 2 was 6.2% that was at the time of the light set. Doesn't give tps. Maf. Thanks craig
Mar 10, 2015 at 2:53 PM
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ASEMASTER6371
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the high percentages on long terms are what triggered the code.

you have a vacuum leak somewhere. it could be intake, pcv or hoses but as long as the percentages are that high, the codes will stay active

Roy
Mar 10, 2015 at 2:57 PM
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LALFAN1960
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OK I did find an issue with a hose. Trying to get a new pcv thru ford. Can't use just a regular one. Right now at idle I have bank 1is 12.0% bank 2 is11.0% they jump around a lot depending g on driving. Negative number to a positive. On the intake gasket part can one try to tighten it at all or don't help. Wasn't sure what % I had before the lights came on. Hadn't scanned it then. It is running good at this point. Thanks
Mar 10, 2015 at 3:08 PM
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ASEMASTER6371
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the long term trims need to be under 9 percent

Roy
Mar 10, 2015 at 3:09 PM
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LALFAN1960
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When I'm driving long term will hold about 6-7%
Mar 10, 2015 at 3:12 PM
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ASEMASTER6371
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idle is the most important time. it needs to be the same at that time as well

Roy
Mar 10, 2015 at 3:16 PM
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LALFAN1960
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OK will try the new pcv tomorrow and I might check intake bolts to see if there tight. Not sure about any other hose. Someone wants me to make a smoke machine to test for leaks so that might be next
Mar 10, 2015 at 3:21 PM
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ASEMASTER6371
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smoke test would be good
Mar 10, 2015 at 3:36 PM
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LALFAN1960
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OK. Will try pcv then go to smoke if that don't work. Thanks for the info
Mar 10, 2015 at 3:39 PM
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LALFAN1960
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Well Roy I put in the new pcv and at idle I'm down to 8.5 % at idle. How much better should it be. Still plan on doing smoke test hopefully this weekend. Have to get it made yet
Mar 12, 2015 at 3:30 PM
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ASEMASTER6371
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that is a good reading. clear the code and drive it

Roy
Mar 12, 2015 at 3:35 PM