Yesterday afternoon on the way way home from picking up my new wheels and tires, i was caught in some torrential downpours which caused some major flooding. A few spots the water was at least a foot deep, i was able to drive through no problem. *(nitto Terra grapplers are as good wet as advertised) Went home, parked the truck.

This morning I hopped in the truck to run some errands, upon start up, the check engine light came on.Made one stop at the bank (shut off engine).
Went to Advance Auto to use OBDII scanner. That particular one only sells them. Jump in the truck to head to Autozone.....upon start up...NO check engine light...OBDII scan...NO codes!
Was this just my trucks way of telling me it doesn't like splashing around in deep water...maybe some thing got wet, but after a good drive, dried out and reset???

1999 ram 1500 slt 5.2 spectre cai, cat back dual exhaust

 

It's hard to know what they're thinking when they're being mysterious.

No CEL, no codes, running well = no worries.

 

my father had the same thing happen to his ram....it was the 02 sensor getting wet, and the CEL would shut itself off....(96 ram 1500 5.2 2wd OBD2)

 

i know cars that if they just hit a puddle or close the hood or trunk to hard, the check engine or service light comes on. But goes off shortly after

 

This same thing would happen to my dads truck everytime it rained, i was finally able to get the code pulled before it shut itself off, and it was a 02sensor code.....exact same problem as yours....never made the truck run any different. and would shut off within 20 miles everytime...sometimes it would shut off if i just start it, shut off and start again, it would be gone...if i started it and just ran it...it would last no more than 20 miles

 

And there is a good check engine answer!

 

I got an occasional CEL while driving sometimes. Shut it off then back on and it's no more. Mine was a mix of O2/EGR readings the one time I scanned it. If it's not permanently on, I see no problem with it.

 

anytime i drive through huge puddles mine does this same thing. i dont ever worry about it, since it doesnt change how its running. the truck just likes to get fussy and complain about stupid things that dont matter. you know kinda like a girlfriend

 

Mine throws a P0420 code every so often because of the empty cat, but if I don't clear it manually it will go away on its own after X amount of drive cycles, usually a week or 2