does anyone know any way around these codes because i cut my converters off and made a y pipe and now im getting unsufficent flow to egr & i have a straight 3 in flowmaster exhaust with super 40 muffler and i want to know a way to get my check engine light off other than taking the bulb out.

 

Black tape over it works also .... speaking from VW experience. And a google of P0411 mostly brings up VW secondary air injection problem. Here are some threads on P0401 in otther forums .... like the ones that have more trucks with OBDII, instead of OBDI like we have here. https://www.ford-trucks.com/ford/truck.php/q-p0401

 

A weak DPFE sensor can cause it too. With the lower restriction in the exhaust, it may be that the failing sensor is now falling outside the expected range values now. A quick test is to use a hand held vaccum pump to apply vaccum to the EGR valve and see if the engine idles rough or stalls at idle. If it does, the EGR is probably ok. Another easy test is to take the vaccum supply to the EGR and use it to apply vaccum to the upstream side of the DPFE sensor, and leave the downstream side open to the atmosphere (and don't forget to plug the hoses from the EGR tube that run to the sensor) and drive it for a few days. Don't clear the codes! Let the computer see the change, run it's tests, and shut the light off on it's own. The computer will have to run all the OBDII monitors if you clear the codes. This way, it only has to run the EGR monitor, and if it passes for 5 consecutive drive cycles, the light will go out. So don't be discouraged, it may take a week of driving to reset the light. If i doesn't go out, check to see if the EGR vaccum control solenoid has vaccum getting to it, and that it is in good condition (should be between 60-80 ohms). If all this checks out, but the light is still on, replace the DPFE sensor. Drive it again for a week, (hook it up properly) the light should go out.