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Q: EGR P0404 code accelerating. 2005 Buick Terraza

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My Terraza has a 3.51 and I got the p0404 Exhaust Gas Recirculation EGR code. I get very poor gas mileage and it’s really slow and stumbles when accelerating up hills. I thought about this and decided to replace the EGR valve with a Delphi EGR. But I still had the same problem. Do I need to reprogram the Powertrain Control Module (PCM)? My Actron scan tool lists reprogramming the PCM as the number one fix for this code. But instead of that I replaced the EGR and still have the same problem. Do you know what the deal is here? Any help is welcome.

For this code, there is a related technical service bulletin 06-06-04-003D dated March 20,2007. The TSB calls for installing a new EGR kit consisting of a new valve, tube, and wire connector, and directions to reprogram the powertrain control module. Just installing the valve is not a complete fix and reprogramming is needed. If you need further help with this, get in touch with a local dealer to see if this repair is covered.

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