Question Check Engine Light, Warm Engine, 1500 + RMP

[BigRedWeather]

Today was the first time I saw the Check Engine light on. It only comes on after the truck is well warmed up and only stays on wnen it is running at 1500 or higher RPMs. I know the Check Engine light can mean about 1000 things, but I would like to start narrowing it down. Are there some simiple tests I can do, with out an analyzer, that will help me eliminate some causes?

For the first time in the 2.5 years I have owned it I saw about 1/8 measuring cup of oil under the engine. I haven't examined the engine yet, but the oil level is fine.

The air temperature is about 20 F. We have had lots of 20 and colder temperatures for the past two months, though.


Thanks,


BigRedWeather

 

[MBRPCrazyford]

That's odd, but it could be the HPOP going bad and not bein able to keep up.