My Toyota matrix 05 threw up these code Po128 and PO116.

There is no thermostat on the engine. It has been removed

Yes no thermostat. Is that the reason for po116

quote author=Dozieson post=123090202]There is no thermostat on the engine. It has been removed [/quote]

Fedrams:
Yes no thermostat. Is that the reason for po116

quote author=Dozieson post=123090202]There is no thermostat on the engine. It has been removed

Is your car having any drivability issue?

The two codes actually signify that something is wrong with your cooling system. As for the P0128 code, you already confirmed that the thermostat has been removed; and this code relates to the thermostat. If you plug in an OBD II scanner that can do a live data analysis, you'll see that the temperature does not reach 75 degrees Celsius (167 degrees Fahrenheit). Also you'll see that your temperature guage barely gets to the middle. Also, I'm sure the fan has been bye passed and it's running directly. All these contributed to your car not reaching the optimum temperature it is designed to operate.


To solve this code, you'll need to install your thermostat back. However, before you do that, kindly perform a coolant pressure test and also, bench test the thermostat to be used. This is necessary so as to avoid overheating.


As for the P0116 code, it's related to your Engine Coolant Temperature Sensor (ECTs) (what the rewires popularly call cold start). Most likely since this code is not accompanied with a P0115, P0117, P0118 code, then the probability is high that the ECTs is faulty. However, before you conclude, you can have your technician bench test your ECTs. The resistance values at varying temperature degree should be recorded and compared to a known good or acceptable data. If there is a deviation, change your ECTs. I'm finding it difficult to attach a picture that shows the graph of the resistance of ECTs versus temperature. I'll have helped you out with that data.


PS: Kindly note that this solution is based on the codes you shared, if peradventure other accompanying codes pop up, there might be a little tweak to how you'll troubleshoot it. I hope this helps

It means insufficient coolant. Maybe u bought all those paint and water abro dem wey be plastic of 1 liter and the rest 4 litres na pure water. Quick loose that radiator and sell the car fast. Na overheating dey load so