Originally posted by squee
Anyone know if a malfunctioning coolant temp sensor would cause my h22a to run too rich, and not throw an engine light? Can my ecu store current trouble codes without displaying the check engine light?
yes to all of that, but it wouldn't make a HUGE difference in the air fuel ratio.....but since they're already rich to start with, then it's very possible that it's telling the ecu that it's not warmed up yet and that will cause it to run rich......some codes cause it to stay on, some don't.........could be an o2 sensor too, but it will normally show up as code 1.....doesn't always trip a code though unless there is something recognizable in the circuitry, like a short or a break in the current.....