I have a 2001 Nissan Pathfinder LE and I got the code P0455 and I got a bad 02 sensor code also
I have change out the canister and valve with it so I'm not sure if that's related to my accelerating problem.

When I'm driving to go on the highway if i floor it the gas pedal, It feels like the truck jumps up like its going to speed up ,but just the engine roars loud ,the rpm SLOWLY goes up and the car feels like its in neutral .
The only way i can really go fast and accelerate hard is to slowly press the gas pedal to the middle the floor , then it would accelerate like i wanted. its really more annoying then anything to me . The only thing I haven't replace is my gas tank cap . Can that be causing all of that? or can the 02 sensor casuse all of this as i read on this forum>?

Change your fuel filter. Use Wix 33023, NAPA Gold 3023, they're both identical. See here fora guide on changing the fuel filter.

is that it? i was reading it might be the o2 sensor also since i got the code p0158 p0138 slow response bank p0139...i'm not positive how the o2 sensor or fuel can cause my full throttle acc. but since its winter here i was going to do the full tune up plus 4 o2 and the fuel filter next year

Yeah, probably. The FSM says " When the filter becomes clogged, the vehicle speed cannot be increased as the driver wishes. In such an event, replace the filter". I'd change it more often than that to prolong the life of the fuel pump - a partially restricted fuel filter can make the fuel pump work harder to maintain pressure.

The rear O2 sensor being bad should not impact anything, its only purpose is to check the effectiveness of the cat, unless the upstream O2 sensor is not functioning. Is there an Advanced Auto Parts near you? I got a Bosch OE-style driver's side post-cat (bank 2, sensor 2) for about $50 after tax using a discount code when purchased online. It fixed the P0158 code and fit perfectly.

thanks for the tips , but isnt the P0158 code for post downstream o2? its too cold here to work on the truck and my acura is store in the garage so i wont be working on it anytime soon. i will be stocking up on parts and doing them in the spring. its not a daily driver more of a snow and ice fishing truck thats why i'm not really worry much .

Possible MAF sensor going bad?

Yes, P0158 is post cat (downstream) O2 sensor on the driver's side as I mentioned. Don't worry about it for now, it's just the heater circuit malfunctioning if it's a P0158 code alone.

I too thought it could be a bad MAF sensor, but a fuel filter is a cheaper thing to try as it could cause the same symptoms. Usually a failing MAF sensor would throw a code though, wouldn't it?

Are you able to go over 3600 RPM, Azndjay?

yes i can go over 3600 rpm, it only happens when I want to accelerate hard to merge on to the highway then it would bog down and not go anywhere . if i let off the gas on the floor about half way i can speed up. It is just weird

Buzzman wrote:Possible MAF sensor going bad?

if i have a bad maf sensor , shouldnt it come up on the scan?

A bad MAF sensor usually throws a code. Cleaning it may help - if you do so, be sure to use a MAF cleaner, not something like brake cleaner, etc.

Can you give us a list of all the current engine codes?

p0455
p0158
p0138
p0139

i'm pretty sure the p0455 code is why my truck can accelerate , i just replace the caniters and valve and also took the throttle body our and clean them with carb cleaner , becuase my car was idleing rough before but after that clean it idles and starts up way better . just only acc problem now

So you're no longer getting a P0455 code, just the O2 sensor codes (which can be ignored)? I still say to try the fuel filter first, if that doesn't work I guess replace your MAF with an $89 Maxima MAF.

i still got the P0455 code also but i will try the fuel filter also

Since you replaced the charcoal canister and valve and it didn't solve P0455, try replacing your gas cap. Use an OEM Nissan cap only.

wix fuel filter okay? i was going to stop at oreilly auto to get the wix fuel filter and nissan dealership to get the gas cap onthe way to school to pick up my books. i do know that the fuel cap when tighten it does not keep clicken when its lock like all my other cars , but when i release the gas cap i can hear its pressure . i'll report back tmr when i change the fuel filter and gas cap and reset the light

Yes, Wix is great.

My gas cap will endlessly click if I keep turning it. If yours doesn't, it's probably bad.

yeah i thought it was weird that mine did not click when it closed and its not a oem since it didnt say nissan on it

Non-OEM gas caps can certainly cause problems. I sure hope a new gas cap fixes your EVAP code, it's a pretty cheap and easy fix if it does!

got the gas cap at nissan today and install the fuel filter. the car starts up more smoothy then it did before and its speeds up better now , but i think i found out its my transmission . while testing out my ccar on the highway ...when i floor the gas pedal and didnt let up. the car speeds up fine until its about to shift gears then it bogs down for a sec and then shift gears or kind of jerks into gears.but it does not do this is i just press it half way as compare to full throttle .. maybe my transmission is going out? it bogs down before it shift up into any gear

You may have to ask at the counter at O'reilley to get Wix.

What's the condition and level of the transmission fluid?

1. Drive around for 10 minutes in the city after the transmission is at operating temperature.
2. Park on level surface and apply parking brake.
3. With P selected, shift through every gear and return to P.
4. Pull transmission dipstick with engine idling, wipe clean, reinsert completely, and read level. It must be within the notched areas labeled "HOT". Check for fluid contamination after wiping on a paper towel.

The fluid should be red, and not smell burnt.

i'll try that tomorrow , i'm hoping i dont have to get another transmission.

Is the Bosch filter any good? I am planning to do mine in a couple of weeks

Bosch makes excellent oil filters, so I'm sure their fuel filters will be of good quality as well.

I just clean my MAF sensor and check my trans fluid like you suggested everything seem fine. After , I clean the MAF sensor i went for a test drive , I notice that in 2nd gear from 3,000 rpm to 4,000 rpm it is sluggish before it shifts. I am just going to wait til next spring and take it to a shop and see if they can figure this one out because I'm stumped

Has anyone documented the MAF sensor cleaning process? My Pathy is about to hit the 100,000 mile threshold and I have changing the spark plugs, fuel filter, water pump and thermostat on my to do list already. Cleaning the MAF sensor is also starting to make sense.

Edit: I have also noticed that damaging the MAF sensor when cleaning is fairly common. Should I just go ahead and buy/install the Maxima MAF sensor?

R50-D wrote:Has anyone documented the MAF sensor cleaning process? My Pathy is about to hit the 100,000 mile threshold and I have changing the spark plugs, fuel filter, water pump and thermostat on my to do list already. Cleaning the MAF sensor is also starting to make sense.

Edit: I have also noticed that damaging the MAF sensor when cleaning is fairly common. Should I just go ahead and buy/install the Maxima MAF sensor?

MAF sensor "how-to" is here. I did not damage my MAF sensor while cleaning it - just be careful and you should be OK.

Much appreciated Towncivilian.

I finally got around to changing the fuel filter. I was able to undo the center bolt half way and slide out the filter after removing the upstream (tank) tube. I wasn't expecting the tank tube to keep leaking but I got it under control real quick. Overall it was pretty successful I'd say, no broken bolts and no fires or explosions either.