Check Engine Lite

[Jefe]

While on my way to work this morning I had a clear road and decided to open the beast up since I had been granny driving the last couple of weeks. Down shifted to 4th gear and was at about 2000 RPM when I started to accelerate. By 3000 RPM the pedal was on the floor and it was then that I noticed a reduction in power and the "CHECK ENGINE" light started blinking. I immediately got out of it but the light continued to blink. As I decelerated I down shifted to 3rd and the light went out. At the next stop light I dogged it a little but the light did not reappear. After I arrived at work I did a diagnostic by holding the "OPTION" button and pressed "FUEL" 4 times. It only had one code in 10PCM and it was P0128 C. Has anyone else experienced this?

Stats on my Car:
2003 Z06
5280 Miles
Donaldson Blackwing
Throttle body bypass
178 Degree Thermostat
WCC Air Bridge
X-Pipe
Borla Stingers

Thanks in advance,

Jefe

 

[c4c5specialist]

HI there,
DTC P0128 is designed to detect a faulty thermostat.
Excessive coolant flow through the bypass hose to the throttle body may cause this DTC to set.
A bad ECT sensor can cause a P0128 to set.
I would first check your connections to your sensor. If this is ok, replace your thermostat and reconnect your throttle body coolant hoses.
These power mods, as they are called, do absolutely nothing.
Allthebest, c4c5

 

[Jefe]

Thanks C4C5. I have done as you said but do not know where the ECT valve is located. After putting the stock thermostat back on and reconnecting the throttle body hoses I have another problem. I drove around 30 to 40 miles at different throttle settings and then I down shifted to third and nailed it at about 3000 RPM. As it passed through 4000 it started to miss with a slight reduction in power. After about 5000 it smothed out a little and shifted to 4th. Again it started to miss as it went through 4000 RPM. There was no "Check Engine" light and no codes appeared. I did the codes check to make sure and it displayed NO codes. Is there something I forgot or anything I should do for this? The car has 5331 miles and the only other mods are a Vortex Ram air intake, (removed the Blackwing), X pipe, and Borla exhaust.

Thanks in advance,

Jefe

 

[c4c5specialist]

Sorry I missed the update.
You can check my reply on the c5 tech side.
Allthebest, c4c5