2002 Nissan Altima Fuel Problems

Let's start with what code number it has.

The one pulled from the computer.

The codes were P0171 and P0300.

The first one is related to the air induction most often, the second is a multiple misfire code.

Was the MAF sensor a reman or a new one?

It was a off brand purchased on ebay. It was new and seemed to work fine for about a week, then it acted up again. I replaced the sparkpulgs then with oem ones, didn't help any. I can slowly get it up to speed but it falls on its face and I have to baby it to get it back to speed.

These are the current codes?

Not what was?

I Understand the symptoms.

What I believe is happening is there is a misfire(po300), thus the code, created by the first condition from the PO171. Was that a new or reman or used one that you bought?

It was new, and that was the codes it showed yesterday. We cleared the codes, but they returned shortly after we started the car back up. When we replaced the new mas air flow sensor it ran fine and we reset the computer and then it started doing all the other systems and through the present codes.

Thanks for your time, I will check these and get back with you. What is a defective H02SI?

Heated oxygen sensor- upstream.

Hey sounds like what's wrong with my 02 nissan altima. Runs slower than normal, kinda kicks back Just doesn't drive to it's full extent. I was told also it is my oxygen sensor. This forum is great.

Is there some way to check to fuel pump without removing it? I'm thinking it might be the fuel filter on the pump, because it set overnight and it started up just fine today!

The fuel pressure can be checked with a fuel gauge, it should be 51 psi. The fuel filter is located on the left side of the firewall. I wouldn't go much more than 30,000 miles without changing it or it will create problems. IF it plugs it may allow dirt to get to the injectors or it will burn out the fuel pump.

I removed the fuel pump from the tank today and it has a screen on the bottom of it. I cleaned it, even throw it was wasn't very dirty. I traced the fuel line from the pump back to the motor and their isn't any fuel filter on the left side of the firewall. The car starts up and runs fine now. I'm thinking it might have something to do with the filter on the bottom of the pump. The last time it acted up we left the car sit in the garage overnight and it ran better the next day. I'm thinking there is dirt or foreign material in the tank being sucked up when the car is driven and not letting enough fuel get to the motor. If it does it again I'm just going to have to start all over again! Have a Merry Christmas and a Happy New Year!

According to mitchell and advance auto parts, there is a filter. Unless it is a late 2002, as the 2003 did not list one.

Nope, can't find one. Had another guy look, its not there. Built date on car is 03-02, It started doing it again. This sucks! I got another stupid question, would it have any thing to do with the plug wires? I replaced the plugs, but now I'm thinking about replacing the wires and this has coils ontop of the plugs. Do I replace them or just the rubber boots?

Okay let's regroup for a minute. You can mist the wires with water and see if it acts up to see if it is a moisture issue, and if you replace the wires, then yes do the boots.

I just want to review a minute, You just mentioned a starting problem, is it cranking a long time to start?

Codes po300 and po171 are still present.

The lack of power is still present. Does that lack of power change once it is warmed up or not matter if it is cold or warmed up?

Was the fuel pressure good?

Are you in a cold climate? There was a recall on the altimas for a small screen between the pump and sock that would freeze up and prevent flow.
(can call the dealer service dept. With your vin to see if any outstanding recalls are not done)

//Going after the multple misfire code from the research I have just done suggests pulling the plugs when the engine is cold and pressure testing the coolant for seapage of coolant going into the cylinders.
HAve you had to add ANY coolant?

Are there any pools of oil in any of the spark plug holes?

Did you do anything with that front O2 sensor?

Wow. So I'm not the only one with a "LEMON"

My Altima-02, based in California, won't start during COLD mornings, or most even. I have to pump the gas pedal a bunch of times in hopes it will start before the battery dies. Sometimes it starts and some it does not. And the battery dies. Once it starts it feels ok, but still hear like a gurgling sound when I accelerate, as if something is holding it back from unleashing its raw power. Then I park and in the eve when I have to go home. Same thing again. Pump, pump, pump until either I get tired, it starts, or the battery dies.I

'm so done with Nissans.

Check Engine Light is on
had the Cath changed 2-3 months ago
changed the plugs then too
drained the radiator last weekend
changed the oil and filter

bought a fuel filter in hopes to change it and solve the problem. Then. NO FILTER TO BE FOUND ANYWHERE?

Now, I'm going to check the plugs again.

What's next?

Please help. Thanks.