How can I isolate a vaccum leak on a 2003 Dodge Durango? I already did the spraying of all vaccum hoses and gaskets to no avail. Replaced the booster, because it was leaking internally. I can reset the check engine light, and about 5 days later it comes back on. When it does, I lose cruise control.

SOURCE: Check engine light keeps coming on replaced gas cap already

Your problem is in the evaporative emission system which is designed to prevent the escape of fuel vapors from the fuel system. Leaks in the system, even small ones, can allow fuel vapors to escape into the atmosphere. The light coming on can be caused by one of the following:

1. Defective or loose fuel cap
2. EVAP canister or hose cracked- not connected
3. Purge or vent solenoid defective
4. Vacuum leak at engine Government regulations require on-board testing to make sure that the evaporative (EVAP) system is functioning properly. The leak detection system tests for EVAP system leaks and blockage. It also performs self-diagnostics. You have tried the easy fix, the gas cap. Finding the leak now will require special equipment and testing procedures, might be better left to a professional.

Please let me know if this information is helpful. Positive feedback is appreciated. Thank You!

SOURCE: Check engine light/vacuum leak

First thing to remember autozone people ar not experts in the automative diagnostic world, if they were they would be earning 50 - 75,ooo per year as a technician, not 25,000 as a desk jockey. You need to go to a mechanic that has a computer to hookup to your car and tell you what the check engine light is on for. then you can fix the exact problem instead of poking around in the dark at the problem until you get lucky and have it fixed for a week or two,

SOURCE: Have a 2003 Chevy Impala. Check engine light

Bank 1 is the rear O2 sensor, but experience says to change both. The front one is right behind the engine in the middle of the engine compartment. The rear O2 sensor is on the top of the exhaust pipe, just behind the catalytic converter. But the same code that shows it is the O2 sensor (which is P0420), is the same code for the catalytic converter, or a vacuum leak. Make sure if you do change the catalytic converter, ensure that the new one is OBD-2 compliant. And the vacuum leak could possibly come from the manifold gasket. Let me know what the problem was!

SOURCE: Check engine light has come back for the second time after having change the air filter and resetting. Now receiving a code: P0101 What do I do now?

Probably carbon build up on a sensor. Had this happen on a Ford Expedition. I put it on the highway and hammered it several times. It blew the carbon off the sensor. Light went away.

SOURCE: Cruise Not Available and Check Engine Light on

PCV hose. I had the same problem...Hear air escaping from mine..I just put some hose tape over mine, and when I got the cruise not available and check engine again, sure enough..tape was coming off...replace the hose..problem solved.

Felicia