This car actually has a 3.0L V6 engine and tranny out of 1990 Acclaim installed. It's been running beautifully for years. Now, when it is started cold, it runs great, but after warm up and restart, it runs very rough and has "check engine" light on. Checking trouble codes, it shows 26, which doesn't apply to this car. I've started throwing money at it by replacing the oxygen sensor and the idle air control motor. I also cleaned and regasketed the EGR valve. Didn't help. Seems to be a temperature related, but I can't imagine what. Help would be greatly appreciated.