Why is my gas mileage so bad in a 1991 dodge ram w150?
Asked by dodgew1501991 Jan 06, 2015 at 05:25 PM about the 1991 Dodge RAM 150 LB 4WD
Question type: Maintenance & Repair
I am getting about 5 miles to the gallon and
there is a lot of smoke that comes out the
exhaust. I have changed the o2 sensor and
about the change the sparkplugs. The
check engine light is not on. Are there any
ideas out there of what it could be?
2 Answers
you would have to read the code it could be a sensor that is showing the vehicle is running lean and dumping fuel to richin it up ....//after you changed the 02 sensor did you do a battery disconnect??.....// if you did not do this the computer still thinks it has the old 02 sensor and it will take a while for the adaptive numerator to come down to normal levels ...meaning you might have fixed it but confused the PCM ....// also don't be surprised if you get a down stream 02 sensor code ...a vehicle that old some times needs both sensors to be replaced together ...// but In would try the battery disconnect first ...// also the engine will run rough at first and not want to idle ..and may need to be restarted several times before it relearns
mikeatpriestlake answered 9 years ago
Sometimes a cracked or broken exhaust near the o2 sensor can cause problems like this.