Dear Doctor: I own a 2004 Honda Accord V-6 with 105,000 miles and I’ve always used premium gasoline. The car developed an extended cranking time, but always does start. My mechanic said there is a bulletin to replace the fuel pressure regulator, so I had him do that along with a complete engine tune-up. My mechanic told me to go to the Honda dealership to have the computer reset, so I did but still have the same condition. The dealer technician said using premium gas could also cause the problem. What do you think? Pete
Dear Pete: I do not think the premium gas is causing the extended crank time. I would first hook a scan tool and fuel pressure tester to diagnose the condition. Next, I would look at the coolant sensor’s actual temperature information being sent to the computer. The map sensor and upstream oxygen sensors could be out-of-range without setting a trouble fault code. Identifix lists some additional problems reported by other technicians around the country including EGR back flow into the intake manifold and a leaking seal at the fuel pump module. Alldata lists a complete step-by-step break down on specs and removal of everything I mentioned, along with correct parts numbers.
Dear Doctor: I have a 1997 Nissan Sentra with the 1.6-liter motor. The car has 170,000 miles and runs great. The problem is the “service engine soon” light had been going off-and-on for the past year, but now it’s on all of the time. I went to the AutoZone store and they said it was the downstream oxygen sensor. I changed the sensor, but two days later the light came back on. I took the car to a mechanic and he said codes P0440 and P0446 were showing for the evaporator system, canister purge valve. I did not change them yet. I changed the gas cap. My car is due for inspection soon. Can you help me with this problem? Al
Dear Al: You need to find a qualified technician who understands the evaporator system and has a smoke machine to troubleshoot the system. You could have a bad vent solenoid, faulty charcoal canister, even a rotted gas fill tube. As for the oxygen sensor code, the circuit needs to be checked, not just have the oxygen sensor replaced. A bad wire connection or even a faulty computer can be at fault here. The vehicle needs to be checked fully.
Dear Doctor: I own a 2003 Lincoln Aviator with about 160,000 miles. It began overheating.