What does the FSM say the two code are?
P0401 P0402
- Thread starter landtoy80
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Wayne
Bought by His blood, kept by His power
According to the FSM: P0401- Exhaust Gas Recirculation Flow Insufficient Detected, and P0402- Exhaust Gas Recirculation Flow Excessive Detected.
Wayne S
Wayne S
Wayne is right on the money 
I don't recall anyone having a PO402 though? :-\
I don't recall anyone having a PO402 though? :-\
I got a 402 once after I 'fixed' my 401. I replaced the modulator (which was caked with carbon) and about a week later got the 402. This is when I discovered that the lines going to the VSV were clogged with carbon. I cleaned and or replaced the lines along with the VSV (which I could shake carbon out of like a pepper shaker) and all has been good since.
- Thread starter
- #5
darwood, you are lucky that the carbon didn't get plugged in your VSV.
Actually, I didn't trust the old VSV and replaced it with a new one. I took off the throttle body to get to it and the remaining vacuum lines and I'll be darned if I was to do that again so for peace of mind a new VSV went on.
So they old VSV could have been plugged with carbon. I still have it and may check it one day.
Kurt I'll just say I'm with you and your analysis of the modulator being the evil one in the egr system.
(I just noticed that my modulator pic made it to your FA thread )
So they old VSV could have been plugged with carbon. I still have it and may check it one day.
Kurt I'll just say I'm with you and your analysis of the modulator being the evil one in the egr system.
(I just noticed that my modulator pic made it to your FA thread
)