P0170

[Sally88]

Check engine light back on, P0170. "Fuel trim bank one. Computer recognized rich or lean condition." Any ideas on what it needs? The truck has been getting bad gas milage, 14mpg.

[UsedtobeSmart]

Originally Posted by Sally88

Check engine light back on, P0170. "Fuel trim bank one. Computer recognized rich or lean condition." Any ideas on what it needs? The truck has been getting bad gas milage, 14mpg.

What year is the ranger? And what engine is in it? Lean or rich condition generally indicates something to do with the O2 sensors, so, start there.

[Sally88]

97 4X4 4.0 engine. 125,00 miles. Replaced the MAF last year along with head gaskets and a lot of the emissions. Truck gets 14mpg and I think it should be better. Will new o2 sensors improve gas milage?

[Sally88]

Anybody have any ideas?

[toddler62]

If the old o2 sensors are bad it could improve gas mileage. 14 mpg in really cold weather with mostly in town driving is not unrealistic gas mileage. This might improve with warmer weather or check the mileage when you do a longer trip with the truck.

[DonSor]

Sounds like you got a "six banger". If you do, you got two exhaust manifolds aptly called bank 1 and bank 2. If I'm not mistaken I believe bank 1 is on the right hand side of the engine when facing forward. Check the 02 sensor for that bank and also check the injectors on that bank.

BTW, it is best to replace the 02 sensors when approaching 100K miles. Although you may not experience any malfunction or a CEL indicator, 02 sensors are known to deteriorate after time, meaning that it no longer can shift voltage signals (lean.rich) in a timely manner as it ages. The PCM will attempt to compensate for the poor signals until it reaches a point whereby it no longer can and that's when the CEL comes on. Also, barring any other engine or system problems, it will improve your gas mileage for sure.

[Sally88]

Thank you, I need to ge the truck in to get this looked at. I have been waiting for warmer weather so I can ride the Harley to work...vroooooom vroooooom.....lol