block

alright. at a stoplight my car will have a really bouncy idle and about 500 to 750 rpm's then it will hesitate. and every now and then when i accelerate when its doing this i hear a clunking type popping noise. also a major loss of power below 3000 rpm's when it is doing this. is this the o2 sensor. i know the clunking isnt but the hesitation and power loss?

DanNY

iTrader: (14)

gotta love the weekly O2 sensor questions..
unplug it..then drive it..does it get better or worst or no change?
better (someone else is broken)
worst (O2 is OK)
same (get a new O2 this one is dead)
also run ECU check..
Not to sound mean..do a search on this one..i've answered many many of these questions.
Dan

Guest

This is precicely, almost word for word what is happening ro my '94 Maxima GXE. In fact, it's like someone is surging the engine, even when I have the foot on the brake. This especially happens at the lower speeds. I would also love to get to bottom of thjis issue. How much are o2 sensors, and how hard are they to replace on my own? Do all Maximas have this sensor, or just certain models? Where is it located? What does it look like. I would also like to try this as a remedy to my pronblem...

Guest

dealer quoted me at $150, checkers wanted $180 but that was for the dohc. Don't know if there's a difference. Do you have to reset the computer when you change on O2 sensor??

block

from what i know you can get them for around 100 from courtesy nissan. and a couple plugs to put it in. its located under the car near the exhaust i think. I am starting to think mine is something else besides the sensor. possibly an injector. its so frickin cold hear i dont want to work on my car. -30 windchill.

Blu Max

Hey do you guys think i need a new 02 sensor, i only got like 250 or so miles on a full tank around town, is that bad? I not sure but on highway i might get like around 300 or so. what you guys think?

Blu Max

Hey do you guys think i need a new 02 sensor, i only got like 250 or so miles on a full tank around town, is that bad? I not sure but on highway i might get like around 300 or so. what you guys think?

Matt93SE

iTrader: (44)

that's pretty typical for city driving and limited highway use..

when I set out on long highway trips, I will get 400+/tank, but unless I drive straight through, I'll only get 300-375/tank even on highway.

Canuck

I don't want to sound like a pesimist, but if its not the o2 sensor it might be your ingectors, check to see what they are running at, if its around 25 ohms its ok. I had this problem about two weeks ago, and I had two bad injectors.

Matt93SE

iTrader: (44)

O2 sensor is about $105 from courtesy.
install is simple.
1. crawl under the car with a big wrench,
2. unplug the old sensor (it's the spark plug lookin thing hanging from your exhaust)
3. unscrew the old sensor
4. screw in new sensor
5. connect plug to car
6. crawl out from under car

tough stuff, huh?

Brandon90gxe

yea i only get about 250 ona full tank too, this seemed kindoff low to me, a lil over 16 mpg... ahh what can i do do improve gas milage?

John van de Pol

First thing to think of with bad mileage and rough running engine is too much fuel. This could be sticking fuel injectors, so the cheap easy thing to try is put one or two cans of fuel injector cleaner with a half tank of gas. I run the concentration much higher than one can per tank if trying to dissolve a problem.

No luck: How about the fuel pressure regulator? On acceleration the dropping vacuum causes this device to increase the fuel pressure and thus fulfill the function accelerator pumps used to do in carburetors (remember those). If it is malfunctioning, it could keep the fuel pressure high all the time easily explaining rough running and poor mileage.

If not: Does the car run OK when cold? To facilitate cold running enrichment there is a temperature sensitive "Plug" that lets extra fuel pass when the engine is cold acting as the choke of yore. Therefore, check that if the car runs ok when cold, but rough once warmed up.

Good luck,

John

Foo90SE

Call around about the 02 sensor..if u can find it cheaper go for it..because Bosch makes em all and owns the patent...so it comes down to how much u want to pay hehe.
A sure way to test the 02 is to get a voltmeter and test voltage at the white wire at the 02 to chassis ground. If the voltage stays the same, its stuck(a.k.a. dead). It should fluxuate(sp?) between .1 and 1 according to the data i found.
As expensive as these things are, i made sure mine was dead

Guest

Good my O2 sensor today. Had to go to Abilene TX to get it(hour drive) but it cost about $40 dollars less. Do I have to reset the computer or just put it in and plug it in. I'll tell you if it solves the rough idle and mph problem soon.

Foo90SE

As far as i know, its just plug and pray (plug it in, pray that it fixes your problem ).
BTW how much did it end up being? i can get one for 100 is the cheapest iv found.

block

where is the 02 sensor located. Im going to test mine tonight.

Foo90SE

02 sensor is screwed into the Y-pipe right before the catalytic converter. You have to trace the connector back towards the motor, and unclip the connector from the engine crossmember. If you have a sharp probe of some kind on your voltmeter, stick it in the back of the connector w/o disconnecting it, and ground the ground lead on the voltmeter to the frame/motor/something metal.
If you cant get any signal by sticking the probe in the connector from the back,you may have to skin the wire some(not cut..just shave some covering off of it) and test it like that. thats what i did, and taped it back up good afterwards.

Guest

It cost about $120. Install was a breeze except for the fact I found a torn CV boot on my pass side. Really sucks because I go the driver side replaced and the car aligned last week. Guess its back to the shop.

Guest

I'd you the results of the new O2 but my car won't warm up. The temp needle STAYS at C. It did get colder out but is this normal??

Foo90SE

Hmm...if it should eventually warm up. If not, your thermostat is stuck open not letting any water get hot.
New 02 sensor shouldnt effect this
If u drive it a while it should warm up pretty quickly..mine does in about 5 minutes(its about 30 degrees in the mornings here)

block

Yea I'd say your thermostat is stuck. the needle should go up about half way or a little less then half after driving for a little while.