o2 not switching/running lean

[2ndgen]

hey guys i was talking to a friend of mine and told him of the o2 not switching and he said that it might be caused by a bad thermostat.

any truth to that?
if so wouldnt a bad stat cause over heating or over cooling?

 

[kimcrwbr1]

I suppose it could be stuck open and not letting the engine warm up properly or the coolant temp sensor could be bad giving the computer a false reading. That is the one with two wires to it. If your heater warms up quickly after a cold start the stat is doing its job you can try changing the coolant temp sensor first if the heater is working good. It should be getting hot after a few minutes of running. The engine starts up in a open loop and after it reaches a certain temp it closes the loop connecting all the sensors that allows time for the 0-2 sensor to heat up.

 

[kimcrwbr1]

The coolant temp sensor could also give you the gutless throttle responce If you want just change the t-stat and the temp sensor together relatively cheap to eliminate those variables. I always do the preventative maint stuff first complete tune up, belts hoses, PCV, t-stat filters. Just make a list and buy the parts as you can afford and go all the way through it so you know where you stand. Too many people neglect the little things until it turns into somthing bigger. Spend the money and time now before it gets cold out.