Hello. I have a 1995 Dodge Ram 1500. 5.2 engine. All of a sudden I am getting only between 4 to 7 mpg (was 12 to 15 mpg last week). I have checked for OBD codes and they are: 12, 51, 32, 55. I have replaced the O2 sensor(Bosch) and EGR within the last 12,000 miles. Neither is OEM. I was told by Dodge techs, 12,000 miles ago, that the non OEM O2 sensor was an issue. Is there an issue that these two codes, 51 and 32, together indicate?

208,000 miles on the odometer.
5.2 Gas.
RWD

Thanks

 

These trucks usually hate Bosch O2 sensors.

I'd wager that that's part of the issue.

 

read the plenum sticky.

 

^^ +1 to both, most likely the issues.

 

 

Lose the bosch 02. Check for vacuum leaks, extra air entering the mix. Hole in your tank?
Friends siphoning gas while your asleep? Blown plenum is internal vac leak and I don't think that could account for such a sudden drastic change in mileage. Can really burn some oil though. What are your codes? Not everyone has them memorized.

 

mpg that bad means your really dumping gas.
either O2 sensor is calling for more more more or maybe a leaking injector.

pull the plugs and see if any one is worse than the others.

 

Or a failed temp sensor......