Check Engine Light
 

My check engine light comes on and it won't go off until I reset the computer by disconnecting the battery. The light will stay off for awhile then after driving the truck (97 F-150, Lariat) for awhile the light comes back on. The manual says this is related to cooling problem or something with emissions. I don't want to take the truck into Ford and have them charge me a $100+ to tell me the oxygen sensor or something like that is dirty. Can any one suggest what to clean or change. Any info would be greatly appreciated. Thanks....

ace,
I had this very problem and mine turned out to be the wires that go to the IAT sensor had broke inside the insulation so it was not obvious to me or the mechanic that charged me $35.00 to give me the IAT sensor code. I replaced the sensor and still had the problem and was quite frustrated. Knowing it was in the IAT sensor area I got out my trusty multi-meter and went to work and found it. Anyway thats my story it would be worth looking at.

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Jim
Bright Red, 97 f-150 SC flareside,4x2,4.6,auto tranny, Mobil-1, Superchipped,Supercharged(Powerdyne), .999 tuned TPS, 3 chamber Flowmaster with custom dual outlets at bumper, JBA headers, Hellwig swaybar, steel cowl induction hood(non-functional), Magnecor 8mm wires, Plat-4 plugs, , A.R.E. hard bedlid, Laverne nerf bars, American Racing 8x16 with 315-55-R16 B.F. Goodrich Sportruck TAs, 4.10:1 Precision Gears, ,Monro-Matic Plus shocks.

ace: I'm guessing it's out of warrenty??? I had about 2k on my truck when the engine light came on. Ford reprogamed my computer!!! Who know's why your's is coming on??? You will most likly have to take it to ford to have it put on their dianostic machine.

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97F150 XLT SC 4x4 Flairside 4.6 V8 5sp Dk Toreador Red, 3.55LS
ARE tonneau cover, p255/70rx16 tires (came w/235), Superchip
Pioneer CD w/4 Polk Speakers & Clarion APA5240amp, skid plates
bed liner, side window deflectors, reese hitch, K&N air filter
40s-2chamber Flowmaster, Bosch +4 spark plugs, rustproofing
Better Built Stainless nerf bars




[This message has been edited by Tina (edited 07-10-1999).]

It happened in my '89. Bad ground to the oxygen sensor.

Ace,
My check engine light came on at 40,000 miles on my 1999 F-150 and it turned out to be a bad gas cap which cost $13.45. When the fuel system would try and pressurize its self it would bypass around the seal on the gas cap. The dealer turned the check light off three times because they could not find the problem and it would always come back on about 1000 miles later. With yours being a 1997 model its possible that the seal may have gotten hard and not sealing good any more. Don't know why mine failed so quick. I've put about 3000 miles on the truck since they replaced the cap and so far so good.

94' F-150: I replaced the EGO sensor and the problem was solved. (However, I did have to use a pipe wrench to unscrew the sensor after all other attempts failed!)

Hey Ace- The check engine light can come on for many different reasons. If your unhooking the battery and the light comes back on then you have what we call a hard fault. A hard fault is a problem that is still happening. Your truck is equipped with EEC-V OBD-II engine management. OBD-II stands for on board diagnosis two. This system has a diagnostic connector located under the dash and any OBD-II compatible scan tool can be used to retrieve a DTC(diagnostic trouble code). The dealer or a independent shop can diagnosis this light.
Most shops will charge a hour diagnosis for the check engine light on. Good luck.

My light's been on twice. Once due to failed HEGO sensor and once due to failed O2 sensor. Neither under warranty and both combined cost almost $400 to diagnose and replace. I wish you luck and I hope you're under warranty.

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97 F150 Lariat 4X4 Ext. Cab. 5.4, AT, Tow Pkg, bedliner, white/grey 2tone w/ grey leather, Fact. CD changer, Gibson Side Swept, K&N, Bosch Platinum +4's,Michelin LTX 265/70 16, S/D Triton V8 emblems, Both doors cracked, Piston slap quieted by Mobile One & Slick 50 Synthetic.

I just installed Airaid FIPK. First start up everything worked great. Second start the C.E. light came on. I cleaned the MAF sensor and reset computer (disconnect battery for 15 minutes) 3 times. I can drive or let idle as long as I want the first time, but the second start up after system initial check the C.E. light comes on. Motor runs fine when light is on. Anyone got any ideas or knows what's wrong?

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1997 F150 Lariat F150IslandBoy
SuperCab, Toreador Red w/ Gold, Styleside, 4.6L, A/T, A/C, 3.55 3800 Limited Slip, Class 3 Tow Package, Leather Captain Seats, Sliding Rear Window.
Modifications:
Airaid FIPK, Bugflector II, Viper 500ESP Alarm, Pendaliner Bedliner, Cobra Trapshooter 3 Radar Detector, CARR Tubular Nerf Bars, NFA 1400 Compact 55W=>85W Halogen O.E. Lights, Durango 255/70R16, Chrome eyelet tie downs, Smoked front lic. plate cover

Did you refuel since the installation? Have you checked to make sure your fuel cap is on tight? The check engine light will come on if the fuel cap is not on properly or the seal is damaged.

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2000 F-150 XLT, 4x2, 5.4L Supercab, LEV, Superchip, Styleside, Black with silver two-tone, 3.55 rear, class III towing package with heavy duty cooling package, Heavy duty shocks, 4 wheel disk ABS, overhead console, sliding rear window, keyless entry, dark graphite interior, in dash CD, factory leather wrapped steering wheel, FORD bedliner, FORD black tubular cab steps, K&N air filter, mar-hyde rubberized undercoating, Modine climate filtration system, Bugflector II, Mobil 1 oil and filter, Build date 7/00

No, I haven't refueled since installation. I already know about and checked the fuel cap thing.

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F150IslandBoy
1997 F150 Lariat
SuperCab, Toreador Red w/ Gold, Styleside, 4.6L, A/T, A/C, 3.55 3800 Limited Slip, Class 3 Tow Package, Leather Captain Seats, Sliding Rear Window.
Modifications:
Airaid FIPK, Bugflector II, Viper 500ESP Alarm, Pendaliner Bedliner, Cobra Trapshooter 3 Radar Detector, CARR Tubular Nerf Bars, NFA 1400 Compact 55W=>85W Halogen O.E. Lights, Durango 255/70R16, Chrome eyelet tie downs, Smoked front lic. plate cover.

My check engine light came on about 15 times during a 32 day trailer pulling trip. I reset it by disconnecting the battery, but having done so, the dealer could not diagnose the problem. I took it in on the 16th time with the light on and it was the left oxygen sensor. Hasn't come on since it was replaced.

I had a similar problem, turned out to be one of the oxygen sensors. Replaced it and everything was fine. Total cost was less than $100.

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'98 F250 LD, 4x4, 4.6, 3.73,Superchip, K&N FIPK, Granatelli MAFS, Borla Cat Back Twin SS Out-The-Back, Bosch +4's, Michelin 265/75/16 E ATX M/S, Rear Lift Bags
HIPER 130/110W Superwhites, Edelbrock WTB

You can get a good code reader from autozone for about $100. Until you know what the code is, it could be anything.

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http://www.mindspring.com/~acbradley/mini2.jpg
The Truck: 1997 Black F-150 Flareside. Regular Cab ORP and Towing Package
The Mods: K&N Filter, Eurolid Hard Tonneau, Profile Windstream Side Deflectors and Lund X-Terminator Bug Deflector.
The Site:
Triton's 4.6 Liter Web Page

I had a problem with the check engine light three times around 15,000 to 16,000 miles. They replaced the O2 sensors on two different occasions and on the final repair they replaced the EGO.

The interesting part was that after the repairs, my feul mileage increased by 2 to 3 mpg. I went from an avg. around 15 mpg to a little over 17 mpg.

-Nate

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Black 1999 F-150 XLT Sport 4WD 4.6L V8 (removed 4x4 sport sticker) Reg Cab, SB, Styleside, 3.55 LSD, 5 Speed Manual Trans, Visteon CD-6 changer, Midland CB, Ford/Duraliner Bedliner, Black Westin Nerf Bars

Future Mods - Black Westin Brush Guard and Snuglid Tonneau Cover

Same thing happened to my 97 F150. The first time it was the HEGO. When they replaced that, they supposedly installed a piece of aluminum to deflect the air conditioning condensate from the plugs. From time to time, if I'm on the highway with the a/c on, my check engine light will come on. It always clears in a day or 2.

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97 F150 4X2, 5.4, Tow package,K&N filter, true custom dual exhaust, stock 16" rims and 235 Firestones (waiting for the recall to include these!),Truck constantly mated to a Stratos 201 Pro XL 72 mph bass boat....

For everyone's information. I posted earlier about my C.E. light coming on every second start up after resetting computer. It doesn't matter if I idle for a few seconds or drive 30+ miles. The first start up no C.E. light.

Well, I found out that during my instalation of my Airaid (with the help of my 2yr grandson not reccomended) I forgot to install and hook up my IAT.

Why wouldn't the computer see the problem on the first start up?



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F150IslandBoy
1997 F150 Lariat
SuperCab, Toreador Red w/ Gold, Styleside, 4.6L, A/T, A/C, 3.55 3800 Limited Slip, Class 3 Tow Package, Leather Captain Seats, Sliding Rear Window.
Modifications:
Airaid FIPK, Flowmaster Delta Flow 50 Series, Bugflector II, Viper 500ESP Alarm, Pendaliner Bedliner, Cobra Trapshooter 3 Radar Detector, CARR Tubular Nerf Bars, NFA 1400 Compact 55W=>85W Halogen O.E. Lights, Durango 255/70R16, Chrome eyelet tie downs, Smoked front lic. plate cover.

check engine and bad transmission
 

Ok, I have had the check engine light coming on the last two days. When the truck is cold, it runs fine. As soon as the temp guage reaches the half way point, the tranny starts to really suck on shifting. It goes slow and engine runs rough. I took it down to autozone for free check engine. They hooked it up but did not get any error codes. Any clue or has anyone had something similar to this problem. F150 1995

Thanks

Eric

You can try pulling the vacuum line off EGR valve and plugging the vacuum hose (for diagnostic purposes).

The way I understand it the EGR valve does not start working until the engine is warm and the rpms are high. If the EGR valve is open too wide then the engine may stall/die/quit running which might be the problem.

https://www.f150online.com/forums/sh...engine+warm+up

Because the computer requires two consecutive drive cycles to turn the CEL/SES light on for non-critical conditions.

As for all you guys that are throwing out ideas because of your own experiences, thanks, but it really is not at all helpful AT THIS POINT. There are several dozen sensors under the hood with several hundred different possible onboard diagnostic codes that the computer can set. Until the codes are read, guessing is about as effective as farting into a hurricane. Once codes are in hand, a logical diagnostic procedure or an educated guess is posible. FWIW, the most common reasons for a CEL, in no particular order, on these trucks are vacuum leaks, EGR sensors and clogged ports, O2 sensors, and misfires (96-on).

Eric: With nothing more than a paperclip and some time, you can pull your on codes on that 95. The drones at AZ just checked for stored codes but did not run the KOER (Key On Engine Running) tests. That test, or the CBT (Cylinder Balance Test), will be the most likely ones to provide diagnostic clues in your case. Instructions can be found at www.fordfuelinjection.com and elsewhere, perhaps even somewhere in this site. I would try temp1's suggestion about disabling the EGR valve and see if the drivability improves. You will get a CEL during this test, but it can be disregarded. BTW, welcome aboard!

Steve

check engine and such`
 

Thanks for all the helpful tips. I did break down and buy me a haynes last night and it shows how to run the Diag test with a Meter. Going to try and do that tonight. I also will go and try out that pulling the line of the EGR valve. Would be nice if that is the fix.

check engine codes
 

Well, I appreciate all the help that all of you have given me.

Just ran my self test finally and got two codes on the engine off.

First test. 11 11 which means Good to go for first test.

second test I got

172 right Hego lean
173 right Hego rich.

I am guessing that the right Hego is bad.

but did a engine run test and the code I have does not show anywhere.

4

So, going to do some searching and see if I can figure out what that stands for, for the engine running test. There is only 2 dig and 3 dig codes listed on http://www.fordfuelinjection.com

engine running codes
 

Well, after finally doing a search, was not doing the Engine running test correctly. Found how to do it on this page:

http://www.corral.net/tech/maintenan...-koeokoer.html

After performing the test, I found that my TPS is showing voltage above the 4.5, which means it must be bad, one reason my transmission is shifting incorrectly, makes total sense. And it also is confirming that my right HEGO is all messed up.

Again, I thankyou, all that have inputted to my problem and soon to be final resolution. Hopefully, next weekend I can replace these two parts when I get paid.

Have a great week.