I have a 1991 Legacy with code 24 and it would not fire on cylinder one as per the usual in limp mode with said code.
I replaced the tps and now it fires on all 4 and it's a new pre-calibrated IACV. Is it possible calibration is off? All the wires have been rebuilt/replaced that got to the iacv. I put in a new ecu and it runs a tad smoother now at least.
Symptoms:
-Cold engine must be revved to about 1.5 to 2k for a few seconds so it's a tiny bit warm to run decently enough. Warm engine is fine.
-Idle is higher than it usually is.
-Automatic Tranny; Shifts to soon and makes it bog and struggle to speed up
-Overdrive engages and stays engaged until under 40 mph which it never did before.
[Symptoms are the same across both ecu's except the old onw just made the idle a tad rougher.]