How do you fix 2003 impala 3.4 code p0401?

Answer 1

When a code is thrown by the ECM, people always buy and throw the major part involved at the car. Half the time, it's not the major part involved that's the problem. It can be wiring, hoses and other components that work in tandem with the major part or system.

In your case, the code involves the EGR valve. I always like to troubleshoot problems such as this spending the least amount of money possible. Start out with the free and simple solutions first, then work your way up if that doesn't solve your problems.

You can start by taking a piece of wire hanger and running that down the passages and ports connected to the EGR. Often times, there's carbon build up in these areas. If this doesn't, help then start looking at the EGR valve itself. You can also try using some carb cleaner in these ports and passages. Hope this helps!