If you have concerns with the way the transmission shifts, have it checked out before it gets worse. Some problems, if caught early, can be less expensive to repair. If your truck needs a newignition coil, it's a good idea to replace all the spark plugs as well. At least once a ye...
Any DTC relating to these sensors must be resolved prior to addressing P0400 code. P0401 Error Description EGR Flow Insufficient Detected The EGR system is monitored during steady state driving conditions while the EGR is commanded on. The test fails when the signal from the DPF EGR sensor ...
not an EGR valve problem or an EGR valve that is plugged up with carbon (though this can also set a P0401 code). An aftermarket replacement DPFE sensor costs less than $50 and usually gets rid of not only the P0401 code, but also the P0171 and P0174 codes, too. ...