Trying to figure out whats going on, changed the tune in the truck today and found codes P0401 and P0404. Tuning and exhaust only. Could they be old stored tunes (didnt trip CEL) or is because of the exhaust I installed?
EGR codes
- Thread starter racinmike77
- Start date
I've always had those codes. There nothing to be worried about. They will be stored in the ECM but the truck under certain conditions will kick the code. It's because of the exhaust, atleast that's what i'm told. They have never caused a CEL in my truck. My truck is not a Cal emissions truck though.
on edit: I think it's beacuse the EGR system has less rescition and that's what causes the codes. it senses' (sp?) "too much" flow.
on edit: I think it's beacuse the EGR system has less rescition and that's what causes the codes. it senses' (sp?) "too much" flow.
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