has anyone heard of changing the thermostat on a stock TPI and NOT the chip and having a problem?

 

Sure, as long as you don't go too crazy. Going from the 195 factory 'stat to a 180 has been done with no problems.

The risk of going to a 160 is the closed loop enable temp in the factory chip...you'll run open loop pretty much full time. The cooling fan settings are also an issue, as they don't come on until >200degF. The lower stat will help on the highway, but in traffic you're up against the fan settings.

 

so no codes? with or without a 160*?

 

GM 165 and 730 ECM's do have a code for "Coolant temp too low" however this likely will only show up at extreme low voltages I would assume...


In these seasons of fall/winter/spring at a sustained rate of speed at low RPM's with a 160 or lower thermostate its safe to assume you'll end up below the closed loop enable temps of about 104° for I believe the arap bin or 95° for the Aujp bin, in at least parts of your cruising, which will cancel your chances of highway mode, which will keep you from leaning out to about 16:1 a/f ratio, which will negativly impact fuel mileage, then when you come off the highway for example and want to have some 'part thorttle fun' while your temp is still low, it wont be so fun when you're running too lean/rich because your ECM isn't managing the ratio with the 02 due to being in open loop.


These are only my opinions

 

i live in new hampshire and weve already had two snow storms so the weather is COLD, i drive my car everywhere, NO CODES, 160 stat, two fans running, A/C radiator removed and throttle body bypass. FACE IT getting codes from changing to a lower thermostat is

 

I figured your just lucky.

 

Hardly likely. If you have problems with this with a 160 stat, it'll do it with a 180 or 195 too. At 104 degrees, all of the thermostats will be completely closed. A 56 degree drop in the amount of time for the coolant to get back up to the thermostat to shut it, I'm sorry but I dont buy it. I've never seen it happen either. Maybe if you lived in Alaska... but then again, I'd be willing to bet you would have problems with other thermostats too.

You can change it to a 160 and not set any codes. I've done that on more than a few cars. What will happen is some devices (like the EGR for example) wont function at 100%, or some not at all. This is because the enable temps are higher than 160, and you never get there. It'll run on the rich side almost all of the time, and the oil will not be up to temp. Its good for racing, thats about it. Even if you lower the enable temps, I think it should still only be used if you are racing. For a street driven car where there are other factors and all out power isnt important, I think its a mistake to run a 160. Theres no good reason to do it.

 

there is no sensor in the EGR? what will the ECM do when the EGR doesnt open, nothing? remember we are talking about a stock chip so there would be no lowering of nothing as far as ECM.

 

i have my egr disconnected and there is no codes :lala:

 

so why dont you explain to me wht the sensor there does? since I GUESS it has nothing to do with the ECM?

 

:nono: :hail:

 

The sensor in the EGR valve is a temp sensor. I've disconnected it on numerous cars and the ecm didnt care. However, if your car is the 91 in the sig, it'll probably set a code if you bypass the EGR. SD cars seem to be real sensitive to that. I've never had a MAF car set a code on me. Doesnt instill too much confidence in the error check for me on MAF cars

Why not just turn off the diagnostic for the EGR on the chip?