Stumbling fixed, read this
Posted: Sat Apr 07, 2012 9:14 pm
It appears at long last that constant misfire, terrible gas mileage and poor acceleration, stumbling especially upon acceleration from a standing position has been solved(I hope). A couple of months back, the Pathfinder started this stumbling problem and the engine light came on. I took it to a Nissan dealership to find the problem and they said it was the Oxygen sensor and replaced it, engine light went out BUT, the vehicle started to deteriorate even more shortly thereafter and the stumbling became a real issue with misfiring happening and terrible acceleration and woeful gas mileage. Everyone assumed it was something else since the oxygen sensor was brand new and no enging light on the dash. We tried everything, MAF, ignition, tested the coolant sensor etc etc. The vehicle always started fine and never stalled and was great for the first few miles each day so I replaced EGR valve, EGR temperatutre sensor, wires, fuel filter and all the usual suspects. Finally, after all that, went back to my 6 week old Oxygen sensor and disconnected it, Pathfinder runs perfect. Nissan had put in an aftermarket sensor which I found out is quite often not compatible with the computer. Aftermarket sensors I have subsequently learned can be a real problem. Also, Nissan changed the oxygen sensor mid way thru the 1994 model year and depending on the date the vehicle was actually made, it makes a difference which sensor is right for it. Aftermarket sell one for the year so you can see where the issues can start. I am a little pissed with Nissan for all the hassles and expense that I have had to put up with for the past couple of months and will hand deliver this piece of ---- oxygen sensor back to them for my $ back next week when I get the right one and put it in. Something to think about with regards replacing sensors, just because the engine light goes out, doesn't mean a damn thing.