Thread: engine code

My 2001 GTap like throw a Po128 and p0300 code... so far i have replaced spark plug and and spark plug wiree, i will be replacing tye thermostat, temp guage and coolant level check sensor. The same code comes and goes.. so the CEL eill trip and will turn off without havimg to reset PCM. Should i drain coolant and refill with a stronger mix of antifreeeze?? Could this be a bad fans or coil packs?? I only see 2-5 misfires and that goes away to after a few kin of driving the car.. i do notice at WOT the temo guage goes up by 25 degrees or so..

I had a 180 degree thermostat in without the proper tuning, and I had that code P0128 pop up from time to time. it mostly happened on cold days when it took a long time for the engine to warm up.

The pcm is tuned from intense and its 180 tstat, no flashing when flooring. The CEL turns its self off , from a cold start will turn back on after driving forbten mins. So a 195 wont trip CEL

if the engine code P0128 is popping up, the pcm hasn't been adjusted for the colder thermostat. the 195 is the normal thermostat and won't cause the code to trip. the other thing that can cause the code to pop up is a drilled thermostat because it won't be able to close for the engine to warm up like normal.