P0401 and engine stumble under acceleration

[JArson]

My 97 fzj80 is throwing a p0401 and stumbles under acceleration. I have changed the egr, modulator, vsv and replaced the hoses xcept for the hoses with the T that leads to the plenum. and cleaned the pass-thru on the manifold. Any suggestions before I do the other hoses?

 

[Splangy]

Are the two vacuum ports in the throttle body clear? Clogged vacuum ports wouldn't explain the stumble, but could explain the 0401.

 

[JArson]

That I don't know. Next weekend I am committing to removing the plenum, changing the final hoses and cleaning.

 

[tominboise]

While you have it apart, consider cleaning the MAF and also replacing the fuel filter, if it hasn't been changed in the recent past....

 

[coax]

...and check the wiring harness by the EGR for being cooked. Did you drive the required number of drive cycles or pull power or clear the code?

 

[JArson]

...and check the wiring harness by the EGR for being cooked. Did you drive the required number of drive cycles or pull power or clear the code?

Cleared code and drove on the freeway till the code came back. It reports two codes 401 and 401 pending