Pmoore304

These replies are great!!! I'll order a new MAF sensor before I do the spark replacement. I sent the car in for a tune up about 9 months ago when these problems first started, and my mechanic cleaned the MAF and it ran much better afterwards, but I could tell it still wasn't 100%. Thereafter, it has slowly gotten worse, etc. He did not replace the plugs, which I had asked him to do, because when he cleaned the MAF the codes cleared. Hmmm. Time to roll up my sleeves, I think, and do the job myself. I used to rebuild engines in high school, so I know my way around the fire wall, but I confess to that being almost 30 years ago. I've done plenty of shade tree repairs since then, but nothing too involved after I became gainfully employed! Before I start the job, I'll get the codes read and post them. I'll try to do that tonight and will pick up the plugs at that time. I noticed no one mentioned the fuel filter as a possible culprit. I still want to R&R the in-line, both because it's cheap and to eliminate it as a possible culprit. I've got some time off with Christmas approaching, so it is time to wake the mechanic in me and get dirty again. I'll let you know how it goes!!!!

I have a 2001 Pathfinder SE3.5 with 150k miles on it. I’ve had it about 6 years and it’s been a great car, one of the best I’ve ever had. I’m about ready to hand it down to my teenaged daughter, but recently it has been having what I assume are mass air flow sensor problems, or else transmission control module failure, or perhaps just a blocked fuel filter or bad fuel pump. The symptoms are: On a cold morning, the car will start perfectly but if I don’t let it warm up for a minute it will bog down badly and not “accept” acceleration for the first 100 feet of driving. Then it kind of hiccups and cures... until higher speeds. In town it performs perfectly. At any time when I’m highway driving I have to accelerate gently to avoid what I believe is “flaring” between gears. It almost feels like it is slipping out of gear from one gear to the next, but I believe it’s more of an engine torque failure. I’ve had transmissions fail me before, and this feels different. At high speeds over 70+ the car will suffer intermittent torque reductions, like it’s starving for air or fuel. It’s impossible, for instance, to put it in cruise control above 70 MPH. When I do, when the engine torque randomly drops the cruise control module tries to compensate by attempting acceleration, which makes the problem worse. Out of cruise control, once I reach speed it will do great for awhile and at random moments I’ll feel a tremble in torque and I’ll have to ease up on the accelerator until the “tremble” passes. It’s a pain to maintain normal speed touching on and off the accelerator all the time, not to mention abusive on fuel and safety. The CEL is on, and has been coming off and on for years with no change in performance. Until recently, however, the car performed perfectly so I’ve learned to pay no attention to it. About two weeks ago I sent the Pathy in for new front struts. My mechanic told me when I picked it up that he’d seen the CEL and checked it out, and that it was running lean. He adjusted it. I didn’t drive it for about a week after that, and then took it on a 220 mile trip, during which it ran pretty horribly and displayed all of the symptoms I described above. I’m not taking it on the open road again until I fix this. I’d like to start easy and change the in line fuel filter. I’ve yet to look for it, but in case it’s evasive, could you tell me where it is? I’ll toss a new air filter in there too, just in case. Then, I’m thinking the mass air flow sensor will be my next fix. If the car is still malfunctioning at that point, I might brave an attempt to change the transmission control module. After that, I may throw caution to the wind and drive to the stealership, but I’d almost rather junk it than do that. Writing that make me cringe, because it’s a comfortable and until recently, reliable car, and the body, interior and all accessories are in great shape, but I don’t find dealerships have much incentive to help out a guy like me who is trying to squeeze every ounce of value out of a 10+ year old car. I’ve been reading online and I see lots of entries about 01 Pathy’s with these types of symptoms. I guess I’m looking for reassurance that I’m on the right track. Thanks for your thoughts and any comments you may have. Patrick in Covington, Louisiana.

New user here, hoping for help with my '01 Pathfinder SE. It's flaring, it's bogging down and probably needs a new fuel filter, a mass air flow sensor and perhaps a transmission control module. I've been accumulating these problems in the car for about a year, but recently they've because worse. It's my daily driver and I have had a great experience with the Pathfinder. Thanks! Patrick Moore, Southeast Louisiana