While my SSEi was at the dealership last week getting the Loose Gas Cap problem corrected, the told me that the ECM had a P0128 code in its history. They said it'* probably a thermostat related issue. Anyone here no exactly what the P0128 code is and what the corrective action is? They said the Service Engine light will probably re-appear because of this code, but it has not as of yet.(2 days of driving) I prefer doing my own wrenching as I don't have a lot of confidence in the dealer nor do I care for the price goughing they always put you through.

DTC P0128 Engine coolant tempreture below thermostat regulating tempreture.

This is a minor code that comes up now and then from guys using 180* tstat.

I used to get this code all the time (I use a 160* stat) untill I got a gadget from zzp called an E-stat. The e-stat buffalo'* the pcm into thinking the engine is warmer than it actually is.

Thanks for the response PontiacDad. I figure I'll just put a new "stock temp" thermostat if the light returns as this is my wifes daily driver.