HELLO, I HAVE A 1992 FORD F150. THE ENGINE LIGHT WILL COME ON AFTER THE TRUCK HAS WARMED UP TO NORMAL. I HAVE HAD A FEW SHOPS LOOK AT IT BUT FOR SOME REASON THEY CAN'T GET A COMPUTER READ. I PURCHASED A HAND HELP CODE READER. I GET 311 AS A CODE. THE BOOK SAYS THAT'S THE EGR VALVE NOT OPENING. I INSTALLED A NEW ERG VALVE AND THE ENGINE LIGHT STILL COME ON. I HAVE REPLACED ONE OF THE OXYGEN SENSORS. THE EASIER OF THE TWO TO REPLACE. I HAVE ALSO AT THE ADVICE OF OTHER REPLACED THE THERMOSTAT AND TEMP SENSOR. THE ENGINE IS A 351 I ONLY GET 10MPG CITY 12 HGY WHY IS THE LIGHT STILL COMING ON AND WHY IS THE MPG SO POOR. BEFORE THE ENGINE LIGHT PROBLEM I AVERAGED 17MPG+. I HAVE ALSO BEEN TOLD THAT THERE MAY BE NOTHING WRONG AND HAVE THE DEALER RESET THE COMPUTER. I DID THAT AND WASTED MY TIME AND MONEY. PLEASE HELP--JB

 

311
AIR System Inoperative/AIR System Inoperative During KOER (Bank No. 1 With Dual HO2S)
What may be the culprit of your concerns is the "coffee can" vacuum reservoir just behind the battery. They will tend to rust through. Also, check the vacuum supply(red vacuum line) to the egr vacuum regulator located infront of the coil. And check for any other vacuum leaks. This would explain the loss of fuel mileage.

Robbie

 

What is the best way to look for vacum leaks. Also what is the name to the coffie can so I can pick one up.

 

WHERE IS THE BANK ONE OXYGEN SENSOR IS LOCATED ON A 1992 150 WITH A 351 ENGINE .