1999 Nissan Pathfinder - didn't pass emission test.

[hsal]

Hello.

I have a 1999 Nissan Pathfinder that didn't pass the emissions test. Check engine light is ON.
The mechanic said I needed to replace the O2 sensor(bank 1/sensor1) and the MAP sensor, and they needed to be original Nissan parts.
After the parts were replaced with the original Nissan parts he requested the engine light is still ON.
Already spent a lot of $$$ on it.
What can I do? Anything else could be the problem? How do I reset the computer?

Thanks

Hugo

[Towncivilian]

Get the codes pulled at AutoZone or another parts store that reads codes for free and post the codes here.

[hsal]

These are the codes:

P1105
P0151
P0131
P0160

Again, after I replaced the MAP sensor and O2 sensor(bank1/sensor1)

[Slumpert]

P1105 seems like something I could test for with basic tools. Pull the selonido off and see if you can blow though it with or without putting 12volts though the two contacts is somthing easy to check and then look for vacucme leaks. The other codes seem like O2 sensor stuff and that certainly could be result of clogged/broken MAP system.

Squeeze the vacuum lines here and there and see if any feel "crunchy" inside..

[Towncivilian]

There is no MAP sensor, only MAF sensor.

The codes other than P1105 are oxygen sensor codes. I will post a detailed reply later; I'm on my phone for the time being.

[Towncivilian]

P0131 is a code for the passenger's side front (upstream) oxygen sensor. P0151 is a code for the driver's side front (upstream) oxygen sensor. P0160 is a code for the driver's side rear (downstream) oxygen sensor. P1105 is indeed a code for the manifold absolute pressure switch solenoid valve; my previous reply was incorrect.

Did you replace the MAP switch solenoid valve? If so, what brand of part did you use? What brand of oxygen sensor did you replace the passenger's side upstream sensor with?

I feel that there is a technical service bulletin related to these oxygen sensor codes, but unfortunately my Chilton's online link died a few months ago so I cannot look up TSBs unfortunately. All of your codes have equal priority.

Try loosening and retightening these ground screws:

[hsal]

Hi.
Yes I replaced the MAP sensor and the O2 sensor(Bank1,sensor 1-front/right).
I bought the original parts from Courtesyparts.com (These are the parts number from them: 22365-9E02A and 22690-0W001)

So, I need to replace all the 3 remaining O2 sensors? Do I need to buy the original Nissan or can I buy another brand?

Thank you again.

[Towncivilian]

You'd only need to replace two of the oxygen sensors - left front and rear.

Advance Auto Parts has the cheapest sensors after discount codes. Bosch is the original sensor manufacturer and I've used them without issue. Add these to cart:
Bosch 13228 sensor (upstream left)
Bosch 13257 sensor (downstream left)

Enter discount code A124 to get $40 off the order, then pick-up in store for a total of $114.98 before tax.

[fastpakr]

Wait a minute. If the B1S1 O2 sensor has already been swapped and you're still seeing a lean code (and one on the drivers side as well) that sounds like you're actually running lean rather than an O2 sensor issue. I'd be focusing on fuel pressure and checking the MAF sensor as well.

[fastpakr]

Update - here's the info on the TSB TownCivilian mentioned. I'd follow its info -before- spending money on sensors.
http://www.justanswer.com/nissan/1bitj- ... p0325.html

[Towncivilian]

Bank 1, Sensor 1 is the passenger side upstream sensor. Bank 1 is the side with cylinder 1, in this case the passenger side. However, thanks for finding that TSB, I would definitely check into that before spending any money on new sensors.

[fastpakr]

Bank 1, Sensor 1 is the passenger side upstream sensor. Bank 1 is the side with cylinder 1, in this case the passenger side. However, thanks for finding that TSB, I would definitely check into that before spending any money on new sensors.

Right, that's a sensor he's already replaced.

[Towncivilian]

Oh, I must have mixed up the sensors while reading above. My bad. Hopefully the TSB will help, although the additional ground harness is rather expensive at $115.12 before shipping...

[hsal]

So, this TSB is something that the Nissan dealer must fix it, like a recall? Or just some guidelines for the mechanic to follow?
Thanks again

[Towncivilian]

TSBs are for anybody to follow really, as long as it's within your comfort zone. TSBs are not recalls and you would have to pay out of pocket to have a dealer or mechanic apply the fix.

[fastpakr]

Had no idea it was that expensive. There's no reason you couldn't just use ring terminals and some wire to make your own for a tenth of the price.

Edit - like this guy refers to:
http://x.nissanhelp.com/forums/80981-post2.html

[hsal]

Thank you both for the answers. Ill try this procedure on the TBS. The mechanic who is looking into my car doesn't seem to know what he's doing. He said something about solenoid ... Anyways. Ill keep you posted if anything happens.