P0401 Error...really worry about it? (1 Viewer)

[newtomelx]

P0402

No, just trying to stay under 2300 rpms, around 65ish! Yes, here in Brazoria County they plug into your OBDII port. so no readiness no sticker!!

 

[AppleTech]

Here are my findings on it... had the same issue.

https://forum.ih8mud.com/showpost.php?p=6397466&postcount=33

 

[LCHardriver_02]

After having the P0402 and then the P0401 codes for over 2 years, I fixed mine. The 0402 code comes from the reference port to the VSV being clogged. I ran a tiny drill bit down the port (the one on the back side of the top of the air manifold) until it was clear. That was when my 0401 code kicked in. Over the holidays, I replaced all of the vacuum hoses, the VSV, and the modulator, while also cleaning out my intake manifold. The manifold was very dirty and had several ports almost completely clogged. That said, I think mine was due to several issues and not just one. After cleaning the manifold and putting it all back together, I still had the 0401 code, which was when I replaced the modulator. Code was gone after that.

One other thing I did was pull my EGR valve and let it soak in carb cleaner for a day, which freed up a bunch of carbon in that thing too.

All of this said, to state that your issue could be multifaceted, which may mean taking it a part and checking it component by component.

Good luck,

Jonathan

PS Truck runs awesome, with tons of pep... but that may be due to the new spark plugs too!

 

[BrotherRob]

Resistor mod and call it done. Mine hasn't come back on and even passed emissions.

 

[Flank]

We don't have any emissions tests where I live.

Then you could do the resister mod.

It's really easy and I still have a few resistors left over. I haven't seen a EGR related light in years. Pm me if you want me to mail you my leftovers. Just my ECU will never go back to ready status.

Many states do actually plug into the ODB system and check for a ready mode, as someone stated a "not ready" status or a CIL is an automatic fail or end of test.