[02vspec]

Hey all, I am brand new to this forum but I have been getting a ton of info off here since I bought my 02 spec v, two weeks ago. I really love the car and the owner I bought it from had all maintenance work done regularly. Car is in great shape. The only thing is the ses light is on. I took and to Nissan and $100 later they said I got a P0420 code. Cat failure at bank 2. They told me I should replace the rear o2 sensor and that may fix it, or my cat may be crap, and have to be replaced. All the recall work was has been done. The car runs great and doesn't seem to be burning oil. One thing is after driving the car there is a loud metal ping sound coming from the exhaust area, sounds like its very hot. So anyone got any suggestions? Should I get the o2 sensor replaced or does it sound like I need a new cat? If so I am going aftermarket, what brand is best?

Sorry for all the questions, and I appreciate any help on this subject, hope it is ok to post this in here.

Thanks.

 

[02vspec]

?


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[Bacon973]

I would replace the stock manifold with an aftermarket header and swap out the o2 sensor and space it out.

 

[02vspec]

Yea that's the plan. I bought xs power headers off of eBay. Should do the job well.



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[i68k]

-for starters, you should read this about your vehicles precat failure:
http://www.b15sentra.net/forums/showthread.php?t=135241

-whenever your ses light comes on, you can goto like autozone or something they pull the code for free, saving you $100. otherwise, you could do the pedal dance and save $100 + gas money. it is good to know how to do the pedal dance.

-you got a p0420, your precat is toast, remove it immediately! its recommended you replace it with a catless header, and use the antifoulers method to void the ses light with your new header.

-the loud metal ping when your motor is hot is your precat expanding/shrinking, potentially breaking up.

-you should get yourself a compression test, then a leakdown test if necessary, to be sure your motor is in good working order. you did just buy this car, hopefully its not a lemon. make sure they tell you your compression on each cylinder. you should be 170-180psi on each cylinder.

-the dealership is a business, you dont need to pay to pull codes, or listen to their recommendations about what to fix. most likely your o2 sensor is fine, both o2 sensors need to work properly for the ecu to diagnose the p0420 precat below threshold by comparing values from each o2 sensor.

-finally, bring it back, get another car, your motor will be toast soon. hopefully you didnt get sold a lemon.

EDIT: also, it some states, a dealership can NOT sell you a car with faulty emission equipment. your precat is emission equipment.

 

[nismolucino]

I agree if you bought this car from a dealer and it is the pre-cat they are responsible for the replacement.

 

[jdmulloy]

I agree if you bought this car from a dealer and it is the pre-cat they are responsible for the replacement.

Yeah but probably just for the pre-cat and not the whole engine if it's toast. Still hopefully even a basic 30 day warranty and lemon laws will help you if the engine is destroyed within 30 days of purchase. Any idea if the car was a trade-in? If so was it at a Nissan dealership or another brand? Previous owner could have dumped it on an unsuspecting non-Nissan dealer who probably wouldn't have know about the defective QR25DE.

 

[i68k]

if it is the precat, they are responsible for the emission equipment, and if you had a warranty, the entire motor. the emission equipment failure causes catastrophic motor failure. either the dealership should pay for the motor, or refund you for you vehicle purchase. to see if the motor is bad, you would have to do a compression test, then a leakdown test. nissan has documentation about this precat failure as well. i mean, every inspection they give me the recall sheet saying if the precat fails, certain operating conditions in the motor are detrimental and could cause failure. you shouldve been handed one of these sheets during your purchase or first vehicle inspection.

 

[02vspec]

Wow thanks all for the feedback and here is an update. I just started a new job with Volkswagen believe it or not and my 02 sentra ser spec v was a trade in. I really like this car and don't want to get rid of it.

Last night I put my xs power headers in, it turned out to be a bit more difficult than I thought to do but after many hours I got them in. I used the ghetto sim or spark plug anti fouler on the o2 sensor and after a little dance with the gas pedal the light is gone.

The pre cat looked pretty clean from what I could see, but either way I don't have to worry about it destroying my engine now.

Btw it is not the best sound in the world now. When I hit the gas it sounds like a car that has no exhaust at all. Lol.

For that compression test, should I still get it done? Can I go to any mechanic for that?

Thanks guys.


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[jdmulloy]

Congrats on the new job, am I correct in assuming that your new job is at a VW dealership and not for VW itself? What is your job at the dealership? If you work at a dealership why did you do the pedal dance? The service department must have equipment that you could borrow, unless they are strict and don't allow it.

I think there's a good chance the person who traded in your Spec V knew the engine was about to blow up and dumped it on an unsuspecting dealership. Since you work there I guess it wouldn't be good for you to push them too hard to fix your car, especially if you got a deal since you work there and it was a trade in.

Does anyone give you a hard time for driving a non-VW?

 

[i68k]

he just started, geez, lol. and agreed about the previous owner.


as for the bad sound, it will sound kinda weird, maybe raspy, just make sure its not leaking. check around both header gaskets, esp the donut. you might need a new donut, or fully threaded spring bolts if its leaking down there. cause it shouldnt be overly loud with just a catless header and stock exhaust.

EDIT: btw, yes i would still do a compression test just to be sure since you just bought the car, if it doesnt look perfect, then a leakdown test. and yes, most full mechanics will do this.

 

[02vspec]

Well when I installed the header I re used the o ring gasket. I put my hand around it and didn't feel any air coming out or anything. I think I am going to buy fully threaded bolts for the springs though, it was very difficult to get them on on the new header. Also idk if anyone else had this problem with xs power headers but I was unable to connect the bolt on the side of the two spring bolts. No matter how hard I tried just couldn't get it down and over far enough to make the holes match up.

When I am accelerating a bit harder than average that is when the noise is real loud.

As for my new job, yes it is at a Volkswagen dealership and I am a inventory manager. I deal with the orders from Volkswagen, dealer trades, deliveries, used cars etc. I don't want to bore you, lol.

And no one has given me a hard time for not driving a vw, but they do make me park my sentra a few blocks away from the dealership. Lol

Cheers.


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[i68k]

that big o-ring gasket = donut gasket

you should always replace with a new one, they squish into place.

but get that compresison test and leakdown before you waste your time, and your warranty.

 

[jdmulloy]

And no one has given me a hard time for not driving a vw, but they do make me park my sentra a few blocks away from the dealership. Lol

Do they really or is that just a joke? If you get the problems solved and keep the Sentra you could get a car cover, then no one will know what it is.

 

[02vspec]

Ok maybe this weekend I will replace the gasket with a new one. I'm sure I can get one at any auto parts store right? And at the same time I will get some fully threaded bolts for the springs.

And ya they do make me park a few blocks down but it's more for a lack of parking spots around the dealership.


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[02vspec]

Does anybody know what size those bolts are? And I heard of people using nuts and washers as well.

Also I was thinking about getting the rest of the exhaust done and maybe get a resignator to get a better sound.
I can't stand the sound of the aftermarket header with a stock exhaust, it's sounds like I am driving with an open header or no exhaust at all. It sucks.


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[i68k]

you can get all the stuff at the parts stores. they have donuts, springs, and fully threaded bolt sets. just take off one of your old bolts and get the ride to home depot or something, the bolts will be cheaper at the hardware stores, just make sure you get a high grade, or at least galvanized bolts. its a good idea to get washers and nuts, but only necessary if your header is not threaded. some aftermarket headers its just a hole without threads. and i would fix the donut first, in case thats what making it sound like crap, like said previously, it should sound like theres a leak, or an open cat when you hit the throttle, not like you have no exhaust.

 

[02vspec]

So I could not find long enough fully threaded bolts. And the threads on my header got messed up so, I found smaller threaded bolts and got some washers and nuts, I had to get rid of the springs.

Do I really need the springs on the bottom bolts of my header?
I know that the rest of the exhaust is on those rubber shock absorbers.
Cheers.


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[i68k]

you should be able to find them at the hardware store, i know i got mine at lowe's. you can always get the bolt set from autozone or something, its like $10. if you goto rockauto.com, type in your model, click exhaust, then exhaust bolt/spring, you should see both kinds of spring sets. one has oem looking bolts, the other has fully threaded bolts with sleeves. you want the one with sleeves, as you can always trim the sleeves to the correct size, so you can press the donut into place.

the rest of the exhaust is hanging on rubber, but its hanging on rubber for a few reasons. one main reason is there isnt a flex pipe, so when torque is applied by the motor, the motor will rock front to back, esp if you have oem rubber mounts. this motion follows down the header to the flex point, where the spring bolts are, to absorb the torque. you dont want your exhaust continuously slamming the ground, or your under carriage, every time you press the throttle.