Hey all, new to the forum but am at wit's end. Have a '96 150 which continue to give me lean codes for both banks. Have changed all sensors, filters, etc and found no vacuum leaks...still getting codes. I am not a mechanic, in fact I am pretty bad at this stuff but I keep trying with the help of my neighbor who does know engines and has been helping but we can't seem to find an answer. Any suggestions. I love my truck...293,000 miles and I don't want another so help me keep this ol' gal rolling along!

 

could you define "replaced all sensors"? hows your idle? any drivability symptoms?

 

MAF, fuel filters, CO2 sensor. Truck runs great, no rough idle, no hesitations in taking off, no nothing runs smooth as a baby's butt! That is why I am so confused.

 

co2 sensor....that made me chuckle inside.


did you replace both o2 sensors?

 

both? and you are right O2...getting a little fat finger here...also replace EGR...

 

I have a '96 with a 302 and it gets the same codes when the outside temp drops below 50 degrees. I too have replaced all of the same sensors over the years. When the CEL comes on, and it did yesterday, I usually pull the MAF sensor and clean it, then run a bottle of Sea Foam through it and it goes away for a few months. I figure it may be the injectors, since they have never been changed and it has 265K miles on it. I have a spare set of injectors, but have been too lazy to overhaul them and put them in.

I know this really doesn't help you out, but I figured I'd let you know that I share the same problem. The truck runs and drives fine, but I'm guessing it is burning more gas since the computer is adjusting the air/fuel ratio based on the codes.

 

someone will have to confirm, but you have 2 or 3 o2 sensors on your 96 truck. I'd guess if youre reading both banks as lean, you have one on each manifold and one after the cat. if theyre factory, they've probably been fried up for a while now.

 

Thanks...did the lower by the CC...back to the supply store...

 

better get a visual on the other one(s). there is a lot of funky stuff goin on with o2 sensors around these years, some trucks have a bunch, some have 1.


yours probably has 3, but you should definitely get eyes on them before buying any.

 

A 1996 F150 will have 3 O2 sensors. One O2 sensor for each cylinder bank (V8) or manifold group (6 cyl) and a third to measure converter efficiency.

Since the supposed codes are for both O2 sensors I would look at fuel pressures and seriously clean the MAF.