Expert: Sean Halliday - 5/19/2009

Question
A few months ago my 98 V4 Camry starting having the check engine light come on periodically. I when to get it checked and was given the P0125 Insufficient coolant temperature for closed loop and was told I had a faulty ECT. I replaced the ECT sensor and a few weeks later the check engine light came on again. I ran a scan again and this time in addition to the P0125 code a P0172 code (Air/Fuel Mixture system rich bank 1) popped up. It gives me several possible problems Injector or fuel pressure regulator leakage, Faulty MAF/VAF sensor, ECT faulty or Faulty HO2S/AF sensor. I am planning on making a big car trip in about a week and not sure where to start with the car or if any of these issues might be a big problem for my trip. Any suggestions?

Answer
I assume you mean a V6?Toyota do not make a V4.The mileage can be a fact.With high mileage it is possibly a stuck open thermostat causing the p0125 code and p0172 is possibly a blocked air filter,dirty MAF sensor,air temp sensor,wrong signal from the pcm.One other cause could be a fault in the coolant temp sensor or low coolant in the system.Clean the small air temp sensor in the air cleaner box also.A rich air/fuel mix is not good for the engine as the fuel will clean off the oil supply to the pistons and cause damage.The computer can not go into closed loop,so,the air fuel mix will be wrong until the engine is at the proper temp and this is causing a false signal from the pcm.If the temp problem is fixed,you should be ok as regards to the rich running.