[98rangerjames]

hey i just bought a 99 ranger super with 4.0 auto, the cel comes on when i pull the codes it tells me lean on banks 1&2 i put new upper intake on put explorer hubs on and checked all vacuum lines and lower intatke no vac leaks. driving me crazy. it also surges going down the road like it lacks fuel. any help would be greatly appriciated.

 

[West]

Since you checked for vacuum leaks, I would check and make sure that the o2 sensors are toggling correctly. They should bounce between roughly 200 mV and 800 mV. You could also make sure that the injectors are actually squirting fuel.

 

[rngrdanny22]

My bet would be on the O2 sensors. My truck did that once and it turned out to be the O2 sensor directly behind the catalytic converter.

 

[West]

But but but the rear o2 sensor behind the cat doesn't effect fuel delivery?!?! (Being sarcastic - I got into an argument on a certain Ranger otherforum with someone that was claiming that the rear o2 did nothing but measure the converter efficiency.) I tried telling them that it did effect fuel delivery, but they were not believing me.

 

[rngrdanny22]

Lol either way its still gonna throw a CEL...

 

[98rangerjames]

thanks for the info peoples will be checkin them out. someone told me that the canister purge valve could be bad also or the canister sny thoughts on this. thanks again

 

[Airtruksrus]

Just a thought, my 3.0 taurus was giving the same codes leading to the bank 1 o2 sensors and had all sorts of problems just having a reliable idle. turns out it was a vacuum leak after all, even after checking out all possible lines. Followed it to a section under the intake manifold going to the pcv valve, had been burned on the inner bend and turned the hose soft, opening a hole right at the bend. Hard as hell to find since it had a clamp that was originally installed at the factory. Hope it helps.

 

[Rebel Ranger]

Have you checked the fuel pressure?I've seen it a couple of time where the f/p is boarder-line cause a lean code on banks 1 & 2.

 

[badinten]

vac leak o2 sen or bad injectors hope we help let us know how its going