I keep getting this code that I can not figure out. Its P0004. Doesnt show up on any list that I have looked at. Any ideas? Check engine light comes on but its running well.

 

What did you scan it with? I have heard about this code from people using a Harbor Freight scanner.

 

P0004 - Fuel Volume Regulator Control Circuit High

Symptoms
- Engine Light ON (or Service Engine Soon Warning Light)
Tech notes
The P0004 is an OBDII generic code, but almost none of the vehicle manufactures use it. If you are getting this code, make sure you are using the correct OBDII code scanner for your vehicle's make and model.
P0004 Description
Fuel Volume Regulator Control Circuit High is the generic definition for the P0004; however your vehicle's manufacturer may have a different definition for the P0004 code.

 

I did clear the code and this morning came up with this p0420, catalyst efficiency.
I did just replace both manifolds (exhaust) and all 4 O2s a week ago. Cleaned throttle plate and intake. Runs great! Just trying to pinpoint the codes that are coming up. Bad cat or maybe software in the engine controller? Who knows.

 

Still No code today.

 

Got the P0420 code again

 

I've pulled this code off my truck. And found a lot of info. On what it is. But having a hard time. locating any info. On how to fix