# Ford F150 Check Engine Light



## gmutt (May 9, 2007)

I have a '97 F150 with the 5.4 triton. It seems like everytime I pull something - anything - where I go up a hill my check engine light comes on. I used to pull an 18 foot Prowler in Northern Calif - lots of mountains - check engine light would come on - then go off later. I pulled a 15' U Haul trailer to Houston for my son - check engine light on again after going up a hill - then it went off. Some time later it went on and stayed on. Had it checked out - oxygen sensor was bad. About a month ago I bought a Outback 21RS and was pulling it home went the light went on again and the engine started running rough. Spark plug and coil replaced - fixed it. Then, a week later, I was towing the Outback home from the Blue Ridge mountains and it came on again, but the truck seemed to be running fine. No loss of power, etc. Then, after a couple of days, the light went off.

Can the problem be checked if the light has gone off? Also, why is this happening every time I pull something?


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## Calvin&Hobbes (May 24, 2006)

Yes, it can. A good mechanic with an updated OBD II (most have them now) can check the history of the engine. There are about a million reasons for that silly Engine light to go on (I've had a 96, 98 and now an 03 f-150) from an improperly adjusted gas cap to transmisson/ engine lock up in the torque converter. I had a pesky problem that was traced to a "lazy"(the mechanic's terminolgy, not mine) oxygen sensor, that would only act up while towing. Good luck!


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## Humpty (Apr 20, 2005)

Well, I had the same issue with my Duramax â€" Check Engine Light, but only when towing. A new fuel injector pump (that cost me an arm and leg) fixed my problem.

The way I see it through my non-technical or mechanical eyes, the vehicle computer monitors a bunch of different â€˜thingsâ€™ to make sure they are in an acceptable range. If one of these â€˜thingsâ€™ is operating very close to one of the limits, the extra load on the engine when towing may cause that â€˜thingâ€™ to operate outside the acceptable limit.

I think fuel/air delivery and monitoring systems would be more likely to be influenced when towing.


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## Nathan (Jan 2, 2007)

Most Check engine light trips are for emission laws. Some affect how the truck seems to run, other's don't. Either way, the trouble codes should be stored and a shop can retrieve them to figure out what is going on.


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## Drac (Apr 26, 2007)

You can buy a OBD II reader for less than $100 at most automotive center (or Wal-Mart for that matter). Might be worth getting, they work on any vehicle made after 96 I think.


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## battalionchief3 (Jun 27, 2006)

Bet its a lazy MAP sensor.... let us know.


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## gmutt (May 9, 2007)

battalionchief3 said:


> Bet its a lazy MAP sensor.... let us know.


Thanks for all the replies. I'm going to Advance Auto to see if they can hook up a OBD reader and check it out. Also - any thoughts on installing a Superchip?


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## 2500Ram (Oct 30, 2005)

gmutt said:


> Bet its a lazy MAP sensor.... let us know.


Thanks for all the replies. I'm going to Advance Auto to see if they can hook up a OBD reader and check it out. Also - any thoughts on installing a Superchip?
[/quote]

Can you afford high octane gas every tank for maybe 15 HP gains? If so go for it. I would look into intake and exhause upgrades first though. Even an ignition system like MSD's blaster box and coil before a chip. Now if it were a diesel I'd throw a chip in in a heartbeat.

Keep us posted.

Good luck.


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## dominer (May 20, 2007)

Anytime a check engine light comes on it has something to do with your emmissions. Fuel air mixture, amount of gases being let out or in for that matter.. (gas cap) Impropoer mixture, too lean, too rich.....you get the idea


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## N7OQ (Jun 10, 2006)

The error code will be stored in the computer and you can either buy a code reader or go to AutoZone and use theirs for free. I would check the error code before I do anything else. Something to think about is when you are towing you are using more gas and air so something as simple a fuel filter can cause the problem. I has a MASS sensor on my Ford truck that kept getting the element dirty over time. he sensor is a small coil of wire kinda like a light bulb element, this element is heated and the amount of air passing over it will cool it and cause a resistance change, well it will burn and dust particles and over time it would get soot all over it. I would just clean off the soot with some alcohol. After a cleaning it would run great. Yes I changed my air filter but particles will get by the best air cleaner.


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