9165pt0

Car has been getting less gas mileage lately. i tested it out and sure enough its 2-3 less mpg. also smells rich. and check engine light will come on for a sec or 2 and then go off, for a lil while. usually only when the car is cold and i take off to accelerate. so i pulled codes and its code 31. so i searched it, and i checked out the vac lines that go to the evp sensor and everything looks good. i changed the sensor and took off neg batt cable to reset it and the cel wont come on as much altho code 31 is still coming up. any ideas on what can lead to these problems?

Bubba 95SN

Put a vacum gauge on vacum line at egr. Do the run test. Does it show vacum? If no check to see if there is vacum to the evr. If yes pull cap off top remove foam filter clean replace and retest. Still not switching vacum do voltage check while doing run test. Voltage switch, replace evr. Vacum to egrduring run test. Apply vacum to egr while engine runs, does engine stumble? No, egr diaphram is defective or egr is stuck from carbon build up, replace egr.

Bubba 95SN

Forgot, most likely culprit is the evp.

Bobert

I have/had the same problem. Noticed a major difference when i replaced:

http://www.fordfuelinjection.com/?p=43

And the other two vacuum sensors below this one. There on the passenger shock tower.

It was a pain in the *** finding the vacuum leak, but all three of these sensors were cracked and caused big issues!

9165pt0

so i went ahead and changed the egr position sensor. cel went away for about 2 whole days of driving. but today it was on more than ever. so i pull codes, and its code 31 again. i did not that theres a leak of coolant from the gasker btwn the t/b and egr spacer. is it maybe the coolant gettin into the egr and egr position sensor maybe causing the sensor to mess up?

Bubba 95SN

Replace the egr. When diaphram gets stretched out the evp sits lower thus triggering the code. I got in the habit of replacing them (egr & evp) to prevent a come back.