Service Engine Soon

[alerored04]

so i threw a service engine code last week code number PO128 coolant temp below thermostat regulating temp.

here is how it occured. during the fall my engine temp gauge quit working and i was told that it was the sensor near the thermostat, so i replaced it, and the guage still didnt work, then last week it threw that code, which i am assuming is telling me that i need a new thermostat but the problem is that i installed a hypertech 180 degree thermostat this fall, is it possible for a new thermostat to stick open that soon? will the next one i buy do the same thing or is it doing this because it thinks that the 180 degrees that the thermostat opens at is lower than the stock one so it thinks its open too much or something like that? should i order another hypertech or should i go back to stock? thanks guys.

[-Alero-]

well it never hurts to just take the thermop housing off and look at your stat. see if its springy and mint looking. perhaps the gasket is peeling off, so some coolant gets by every now and then.

i too have the same thermostat you have, i have had no problems.

[alerored04]

i think i am just going to replace it, the part only costs 20 bucks, im sick of dealing with all the bs with the car right now, my hub sensor is flipping back and forth between being fine and lighting the christmas tree on my dash, it glows at night and now this, im fed up with it. do you think that i should replace that rubber seal as well as the gasket?

[-Alero-]

ummm the rubber seal/gasket is what im talking about.

look dude, if yo ucan just flush yoru coolant, and check oput your thermostan, no sense in replacing it if its fine, and the only problem was, the little gasket seal was coming off slightly