03 SE P0404 EGR code

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GK55
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Posts: 9
Joined: Tue Feb 18, 2014 2:06 pm
Year and Trim: 2003 Bonneville SE

03 SE P0404 EGR code

Post by GK55 »

I've been getting a P0404 code for the EGR valve intermittently for about the last week. I've pulled the EGR & inspected the piston (checks ok), housing (not loose or broken), gasket & metal ring (checks ok), connection pins (corrosion on middle pin, couldn't access to clean). I cleaned the EGR mounting plate & mounting surface with carberator cleaner, re-installed. Sometimes a P1811 long shift code accompanies it, sometimes not. There seems to be no issue while driving. Maybe a slight miss or hesitation when moving from a start while the engine is cold. I've thought about replacing the EGR, but haven't as of yet. There has been been a slight decrease in mileage from 26/27 to 23/24.

I'm curious if the 1811 follows the 0404, or vice versa? Could a shift kit &/or PCS swap eliminate both, or could swapping the EGR eliminate both?
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harofreak00
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Re: 03 SE P0404 EGR code

Post by harofreak00 »

They are completely unrelated problems.
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GK55
LE Member
Posts: 9
Joined: Tue Feb 18, 2014 2:06 pm
Year and Trim: 2003 Bonneville SE

Re: 03 SE P0404 EGR code

Post by GK55 »

Thanks for the input. I'm thinking of changing the EGR outright and then going from there. Even though it appeared to be serviceable, it doesn't mean the valve isn't bad, or going bad.
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