i have a 91 firebird formula with a stock 350 tpi motor what is the lowest temp thermostat i can use without cuasing trouble codes to pop up?

thanks in advance

 

I wouldn't go below 180*, I think the ECM has some functions in the 170's you don't want to mess with, unless you plan on getting a different PROM. Someone more into PROMs could tell you for sure.

------------------
1990 IROC 350
Mods: Too busy trying to make it run right to mod it.
Airfoil, Dynomax cat-back, Accel coil, 180 t-stat, Bald Eagle tires,
Hypertech fan switch, Accel 23# injectors, Holley AFPR, ported plenum,
Ruger P95DC, hot wife, new oil filter, thick rubber floormats, no cats.
18.0 @ 85MPH since I'm one big-a$$ MF
"It's better to have and not need than to need and not have."

 

I think that your car came stock with a 190 degree stat. seeing that you live in Minnesota, I would not go below a 180 degree stat. They do make 160 degree stats, but I would not reccomend that for you, unless you live in California or Arizona. However I do not claim to be an expert, so lets see what others say.

------------------
1990 RS Camaro 305 TBI
700R4 Tranny
3" cat back system with flowmaster mufler
Edelbrock strut brace tower and rear panhard bar
Spohn subframe conectors and lower control arms
all polyurithene bushing under the car
March underdrive pully
K&N filter
Hypertech chip
Aluminum driveshaft
3.42 posi rearend
Killer sound system
Many new mods to come

 

I doubt that even using the "wrong" stat will throw a code. Use my handy-dandy "therm-o-matic" to pick the right one.

195º ~ Antartica, North Pole, South Pole
180° ~ Cold or Cooler Climates
170° ~ Warmer Climates
160° ~ Hotter than Hell

~~~~~~~~~~~~~~~~~~~~
Red 86 T/A 5.0 TPI (LB9/WS6)
~HyperTech Cap/Coil/Rotor/AFPR
~Derale Adjustable Fan Switch ~ 170° Stat
~Flow Matched Injectors ~ K & N Air Filter
~Ported Plenum ~ Pirelli 245/50/16
~SLP TB Airfoil ~ All Else Stock