Egr problems P0401 and P0405
#1
Staging Lane
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Background: I purchased my 1999 T/A last year without a SES light on. For the first few weeks I would get an intermittent SES light for egr problems, but the car seemed to run correctly. In November the transmission went out and I had it replaced with a performance unit and a new converter. Right after trans install the car would seen to lock and unlock the converter at odd times and would stutter. One day the car began to stall upon decelleration and a check engine light would appear. I found the rpm would dip real low 2 times and if it dropped too low would stall. This occurred while on the brakes or simply rolling to a stop. On a hunch I unplugged the EGR valve and the car instantly corrected the issues. With the exception of the SES light and part throttle ping it runs normal while unplugged. Now, as soon as you plug the egr back in all of the poor performance returns. Today I replaced the egr valve and nothing has changed, the problems remain while it is plugged in. The SES light is on as soon as you turn the key until the car is turned off. At this point I don't know what to try. The car is way overdue for an inspection and I need it fixed.
#2
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It sounds like you either have a bad EGR or wiring, new parts do come out of the box faulty at times, don't depend on just because it is new that it works properly. I would start with trying another EGR. Then I would take a real close look at the wiring at the connector for it and see if you see any problems.
Also while the EGR is off, start the engine and make sure that you have a lot of exhaust shooting out the pipe that connects to the exhaust manifold and a lot of vaccum sucking through the pipe that connects to the intake. If either one of those tubes happens to be clogged it will also cause issues.
My money is on EGR valve itself or wiring, because of the P0405. That is a circuit malfunction code.
These may also be helpful to you,
http://www.obd-codes.com/p0401
http://www.obd-codes.com/p0405
Also while the EGR is off, start the engine and make sure that you have a lot of exhaust shooting out the pipe that connects to the exhaust manifold and a lot of vaccum sucking through the pipe that connects to the intake. If either one of those tubes happens to be clogged it will also cause issues.
My money is on EGR valve itself or wiring, because of the P0405. That is a circuit malfunction code.
These may also be helpful to you,
http://www.obd-codes.com/p0401
http://www.obd-codes.com/p0405