I have recently replaced the EGR valve on the vehicle and the code went away for about a month. Here recently the code came back on when I first started the vehicle up in the morning. This time the reduced power came on along with the same code p0400, what's weird is in the afternoon when I'm driving home the engine light turns off. The light is only coming on when I first start up the vehicle. The filter is clean all the bolts are nice and tight all gaskets were installed when I replaced the EGR valve. Not sure if its some kind of sensor or what just really frustrated at this point.
p0400 EGR code
- Thread starter sfcrodabn
- Start date
I am running an after market air filter which is about 8months old now. The MAF sensor was replaced about 3 months ago
The crazy thing is the check engine light goes in the afternoon when I go home from work. I noticed when the temp is above 55 deg it’s warmer and the light goes off
I put on aftermarket cold air intake and always had codes pop up, went back to factory intake and no other issues. Almost at 150,000 So wanting to delete DEF at 150,000 is it worth it? Also I was went 28,000 miles before had change fuel filter, started adding Seafoam to tank diesel now I have add change fuel filter 2 times in 10,000 miles, is the Seafoam causing it to change fuel filter more often? No other issues besides these