rough start/bad mileage

[Tosh]

well right now the pathfinder is only a farm truck...but it still gets drove everyday. even on the hottest days the pathfinder every now and then will turn on,run rough then cut off. then i start it back up and it runs fine

i also only get like 8 mpg and i smell exhaust fumes in and outside the truck

any help would be appriciated

[Kingman]

Bad o2 sensor is my guess, along with bad coil or wires, bad EGR valve, or a vacuum leak (heat expansion)

[Tosh]

what do you mean by coils and wires..im not sure what the erg is either...

[k9sar]

I agree on the O2 sensor. I would also check your connector/wires on your MAF.

 

coils refers to the ignition coil (we only have one) located above the passenger side head cover

wires are the spark plug wires. If shorted/broken/high resistance, you will not get spark in the cylinders and get poor mileage and rough running

EGR is the exhaust gas recirc valve that sits on the side of your intake. It takes hot exhaust gas from your drivers side exhaust manifold and feeds it back into the engine.

[Tosh]

oh i know what most of the things are when i look at it just not it's names.haha

but i'll check them this weekend when it stops raining and see whats wrong