I happen to have a 5.6k resistor inline on my IAT sensor. It is on my Ford Escort ZX2 with a 2.0 Zetec. This mod gives more timing on our cars by telling the ECU that the air is colder than it actually is, along the lines of -10°F with an ambient of 60-70°F. The colder the air, the less modification to the signal there is, and vice versa. The IAT is not used for determining AFR on my ZX2, so the computer does not compensate for it. I'm unsure if your Chrysler has the same set up.
As for you check engine light, the IAT wires could have a bad connection and trigger the CEL. I would start there. Actually, go to an AutoZone, Advance Auto, or O'Reillys and let them see what's causing the CEL for free, and report back to us
