Egr

I had a code pop up for my egr po401 so I replaced my egr with a brand new one and my code went away and my truck ran better and I also replaced plugs and wires then 4-5 hours later the code came back and when I start my truck it cranks up rough. This is on a 97 Toyota Tacoma with a 2.7 v4

 

Easiest thing to check/fix ......check everything for vacuum leaks.....
a lot of times old hoses are fine until you mess with them...

double check all your connections....retrace your work.....
......if you havent replaced hoses recently.....might need to do a smoke test....
Also check your pcv connect.....thats a trouble spot for sure.....


Sometimes it takes the ecm a few miles to reset...

 

Try unplugging your battery for an hour. Let it reset and try again. Also check everything he said above. Give us an update.