CEL mystery challenge

[phatboygravy]

Here is a good one that has a few of us debating............

Truck is late '99 auto running:
- TS6 chip
- MBRP 4" turbo back
- K&N intake pipe with AFE Stg2 filter
- 6" lift with 38" tires

Since installing the TS, Exhaust and Filter the CEL light comes on every time I drive the truck, but not in a consistent way to diagnose. Also as soon as the truck is stopped then there is no OBD codes showing.

I have managed to simulate a driving pattern that switches on the CEL light, but can not tie that to a specific problem to go check. Basically after driving a few miles to get the truck warm if I come off the "go" pedal quickly then that triggers the CEL, if I come off very slowly then that does not trigger the CEL all the time. When the truck is cold the CEL doesn not trigger. When the truck is warm I shut it down, restart and drive it triggers as soon as I come of the "go" pedal. So a typcial morning I am a few miles out from home then the CEL light comes on, occasionally [if no one gets in the way] I can drive 10 miles on the way to work without having to come of the gas [much] and the CEL lightstays off [until I totally come off the pedal].

I am thinking this is possibly related to the air sensor.
Anyone have any other thoughts?

[NoRalPh]

It's actually quite simple

The programming causes stuff to go out-of-spec (HiPres oil and the like) and is actually supposed to cause an occasional CEL on some settings & conditions.

And, you don't have the right equipment to retrieve codes (OBD-II generic scanners are of little use with our trucks which are NOT OBD-II). You would actually be able to get the stored codes with the right scanner (Snap-On, Ford, AutoEnginuity)

[CT Performance, Inc.]

Chip and 17* stock pump = low HPO= cel...normal can be fixed with a new HPOP...SRP1.1 or changing to stage 1's.

[Young-SC-Owner]

Could be an overboost code also