CEL while towing

[xltguy]

I haven't had a chance to have the code read yet, but wanted to put this out there to see if any of the list members have an opinion on the reason for the CEL. This past weekend I towed (with OD off) my 18 ft. travel trailer (3500 lbs dry weight) through the Colorado mountains with my 97 5.0L AWD XLT. As during my first experience towing last year, the truck ran great and I had no problems. Except... after driving about 3 hours and about 20 minutes into a 40 minute sustained pull up a gravel road, with switchbacks keeping speed at about 20-25 mph, my CEL came on. All guages were fine and there was no change in drivability. After a weekend of camping and not driving the truck, the light was still on the whole way home yesterday. Truck continued to run fine. Today, driving to work with no trailer, the CEL went off and stayed off. Any ideas? I will try to get the code read in the next day or so. Thanks for any opinions/guesses.

 

[MrShorty]

Without the code, it's just guessing, so get the code before you do anything.
That said, I once saw the same thing on my '92. The code it turned up was an O2 sensor code. Turns out the O2 sensor was bad. Remember, though, you have three or four O2 sensors, so you don't want to just go out and change the sensors until you know they are bad.

 

[410Fortune]

any intake or exhaust mods on this truck?

Traveling through the rockies can get you a CEL, the change in elevation, pressure in the fuel tank, colorado crappy gas, etc can all attribute.

You need to pull the code, otherwise everything is just a guess.


If the CEL went off and stays off then it was likely a sensor (more likely an 02) thgat went out of range for a few,. for whatever reason.
Towing and hill climbs can really screw up the air/fuel at those altitudes.....

 

[Robb]

When I was pulling my X through the mountains of WV this winter with an Expo, I kept getting a CEL throughout most of the trip. Whenever I stopped to get gas and start again, the CEL came on about 5 minutes later and stayed on.

Got home and read it and it was some O2 code. I erased it and the CEL never came on again.

 

[410Fortune]

it seems that long hill climbs and large changes in altitude can set an 02 sensor code, either lean or rich...I would assume the changes in 02 levels in the air cause the 02 sensor to read out of range for a minute or two. My friends Jeep GC does the same thing as well as my GF's Maxima, and my dad's 2002 Wrangler sport.....

I wouldnt worry about it, in other words, Until it comes on and stays on........

 

[xltguy]

Thanks to all for the ideas. I am stopping on the way home to have the code read. I'll post the results tomorrow. Regarding the question of intake/exhaust mods.....all stock (boring, I know).

 

[Rhett]

Luckily mine has never thrown a cel going thru the Rockies. I was on I-70 and later Fremont and Tennessee Passes around Leadville. Other than having no power, my truck did fine.

 

[xltguy]

I went to AutoZone and had the code read. It showed 2 codes,both the same--P1131. Can anyone tell me what this code refers to?

 

[dogfriend]

1

 

[dogfriend]

2

 

[dogfriend]

3

 

[Glacier991]

If you are back home.... and the code situation does not repeat, I'd not worry about it. It did not sound like it affected the performance (driveability) of your Ex. You were in an extreme situation there and the PCM will throw a code on anything likely to exceed 1.5x mandated emissions. You GROSS polluter you. <g>. If it continues let us know, otherwise do not worry. I fret not a lot on non driveability codes.


Happy Exploring

Chris

 

[xltguy]

Thanks to everybody for the information. I'm glad I can ignore it.....as long as it doesn't repeat in normal driving.