I have a 97 explorer I have a po401 code .. I have changed the valve the solenoid and the DPFE ( junk yard DPFE) . the crank sensor , plugs wires coil pk intake gasket iac valve . I had some other codes that call for some of this stuff .. I had a random miss fire .. and I have 2 codes I don't know what they are but they said bank 1 and bank 2 too lean and o2 sensors .. I have had those 2 codes the entire time I have owned the car with no issues .. now the egr code is the only new code and here is what my car is doing .... rough idle and bogs down when I try to give it gas if I drive it some where and get the engine up to temp it might not start until I have let the car sit for about an hour .. im at my wits end with this thing . any help would be great
There are times when it would be less expensive to take the vehicle to a knowledgeable shop and pay for their expertise. Considering all the parts you've replaced, this may have been one of those times....
The DPFE is a fairly common part to fail, so there is a reasonably high chance the used part you installed was bad. But there's also a good chance you have a vacuum leak that is contributing to the P0401 code, the lean codes, the random misfires, and the rough idle. What are the chances with all the parts you bought you also purchased a vacuum gauge so you can check the manifold vacuum with the engine running?
You will also want to inspect the vacuum hoses to the DPFE to make sure they are in good shape and that they did not get reversed when reinstalling. They are slightly different sizes, but not do different that you cannot connect them incorrectly.