Diag codes for trouble shooting po141,po404,po440
Code 141 is the O2 (oxygen sensor) gone bad, needs replacing.
Code 440, 442 and 445 are all in the EES (Evaporative Emission System). They are leaks in the PCM (Powertrain Control Module). It tests this system when there is about one fourth tank of gas left.
This system controls fumes from the fuel by storing it in a vapor canister until they can be burned off. This system has several parts in it. You have the solenoid (which is a vent valve and a purge valve), fuel tank, a vapor canister, and you have lines coming from engine vacuum port, going to the vent valve. But you may want to check your gas cap. This is the culprit most of the time. As we take it off and on, it can cause leaks. This is also the cheapest solution. You'll have to clear your code with an OBD scan tool, to see if it was repaired by replacing your gas cap.
Also older vehicles can have a leak around the fuel filler neck where the gas cap attaches to is a seal and it could have gone bad.
A lot of times that seal is leaking around that filler neck. So more likely than not, it is leaking and/or gas cap needs replacing.
A 403, 404,405 are in the EGR System.
401 and 402 are the EGR valve.
You will get these codes because the PCM has sent them. It will send them to test the system as part of a self-diagnostic test and the other reason it sends it is because it wants to monitor the EGR system through everyday, normal operations.
This is what is known as PCM command. It is looking for correct signal of the wires to make sure they are working right from the solenoids in the EGR valve.
There is a problem in the EGR system that needs fixing. Sometimes replacing the EGR valve will fix the problem, but before you go out buying a lot of parts for your car, have a mechanic shop test the EGR system.
Aug 01, 2012 |
1999 Saturn SL