DPMF & MPG

[Tom Stocker]

Will a faulty DPMF sensor cause bad milage?

 

[Fudged Undies]

DPFE maybe? It's an emissions part, will probably have some detrimental effect.

 

[paul wise]

Yes, when the OBD II computer does not recieve the proper feedback from a sensor, it reverts to a default run mode and turns on the check engine light.

The default mode does not optimize the air/fuel ratio and adjust the timing based on engine conditions (because it is not receiving the proper feedback) so fuel mileage and performance both suffer.

 

[Tom Stocker]

Thanks! I have a feeling it is bad. When I bought my trac the check engine light was on, I told the dealer I won't take delivery untill the light was out. So like any crooked used car salesman, he just took the bulb out. I didn't figure this out till it was too late. But if it only cost me $50 plus a bulb then that is better than fighting with the @@shole.

 

[steve twyver]

If you bought this vehicle recently from a car dealer, removing the CEL to avoid detection of an emmision problem is considered tampering with the emmissions system - a felony. In California, the seller is ultimately responsible for ensuring that the vehicle passes emmision. If a vehicle is sold without certification and it subsequently doesn't or can't pass, in court, the seller will have to repay the purchase price.

 

[Richard L]

If the dealer disabled the CEL they can be charge with a federal crime an probably state crimes. However it will be very difficult to prove they disabled it this long after the fact. I don't know if it's possible to disable the CEL other than removing the bulb or cutting the wire. You can easily test the light by simply turning on your ignition without starting the engine. All instrument warning lights should illuminate including the Check Engine light (CEL).



If you don't get any CEL light, you may want to have someone like AutoZone read any error codes in your OBD computer. If there are error codes and you are not getting a light, then replace the light. If the bulb was removed or the wire cut, that may be evidence that they tampered with the emissions system.



...Rich