I have been reading quite extensively here and may have linked some issues and want some input.

I bought an '05 Maxima in '07 with 5k miles. I now have about 82K. From the beginning, I would smell the "rotten egg" smell when I accelerated hard, but thought nothing of it. Then a few months back I started hearing a noise from the engine. The only way I can explain it is a high pitched "whine" that increases in intensity as the RPMs increases: So when i rev it up or accelerate it gets louder. Then not too long ago I started getting a P0420 code. After doing a LOT of reading on here, it seems that many people have had catalytic converter issues and in some cases have ruined their engines. I am hoping that the "whine" isn't a result of a blown cat converter pushing particles back into my engine. Could all the issues be linked? Any advice as what to do and how to trouble shoot? Do I have one big problem or two separate problems? Now that I have read quite a bit I am starting to get nervous I may have a major problem. Thanks for the advice/help in advance.

 

im glad you found your problem and thanks for informing us all.

next time, please keep your questions, findings, followups, and varieties of your question in one thread. its an unspoken courtesy.

 

Definitely sounds like a catalyst issue. Toyota's are notorious for this as well.

I think most manufacturers cover any emissions control parts up to 75 or 80K.

Here's a bit from the EPA website that confirms it: "Specified major emission control components are covered for the first 8 years or 80,000 miles of vehicle use."

Unfortunately, you're just outside that threshold man... which I know sucks bigtime. I don't think you have to worry about particulate being blown back upstream from the catalyst. The whine you've been experiencing from the engine bay could be the cause of the blown catalyst, but I'm dumbfounded as to how it could be related.

 

I have just read in other posts that the vacuum created when you start your engine can suck particles from the cat back into the engine and those metal shards can cause engine issues. I was just wondering if that is possible or not?

Has anyone had any experience with being just over the warranty on emission related parts? If the cat is the problem, it's quite apparent that it happened before 80k but not sure how strict they are with it being over 80K.

 

if im not mistaken, if you are at risk for this problem, your engine will throw a code first. I don't i've heard of anyone having the particulate vacuum problem on a nonSES light max

 

The trouble is proving that it did indeed happen prior to 80K. Depending on the dealership, they might fight you tooth and nail over covering the cost of an OEM catalyst (which avg around 700-1000 depending on make/model).

My dad actually works for the NoVA Dept. of Environmental Quality Emissions Control sector. He might be able to shed some light on this for you and provide some guidance.

 

I guess I should have mentioned that it did throw an SES light. The SES light may have come up briefly after the noise started but has now come back constantly.

 

Also, is there any way to test a cat without taking it into the shop?

 

replace it. you are running the risk of catastrophic engine failure.

i wouldn't wait one day. if your ses light is on you don't have a choice. you won't be able to pass smog, so you might as well fix it now for peace of mind rather than later when its due to be smogged.

these kinda things aren't worth waiting on

 

GM_Traitor- That would be great

Another question. I was just looking online at cats. Is it okay to buy them online? Will they work okay? Do they have fittings for all the O2 sensors? Thanks everyone for you input.

 

I have had the same issue I'm looking into just doing headers and runing no cats at all

 

But will it pass emissions with no cat?

 

lol NO you will fail the test. you will fail BOTH parts of the test actually, you can't pass visual or metered parts with no cats.

people who eliminate their cats need to find a dirty smog shop or will be spending a butt load in welding cats on and off just to get past smog.

a smarter person will just buy some High flow pre cats and call it a day.

 

change your battery and battery post easy fix

 

its your pre cats. usually bank 1 goes out first then the other. your most cost effective option is to install the high flow pre cats made by racingline

http://racinglineperformance.com/sho...&idcategory=24

 

I'll see what I can do man. You can certainly buy new cats online, but I've seen and heard horror stories going any route other than buying OEM. There's a reason why OEM catalysts are so damn expensive; they last a long time!

Any HFC will crap out sooner than OEM. Plus, if you've got any other bolt-on's like intake and cat-back exhaust, I'd highly recommend a custom tune from a reputable shop with UpRev Osiris software. Got plenty of friends with 350 and 370Z's that needed a tune after installing HFC's (stock ECM can't alter the A/F ratios enough to run right).

In the end, any aftermarket catalyst will work with your OEM O2 sensor bungs and fittings for your '05 Max. Check out Random Technologies, Magnaflow or Berk if you want to give HFC's a try.

 

Thanks for the input.

What are the reasons my cat is going bad? Was it just time they go or are they known to have problems? I want to to fix the problem, not the symptoms. If there is something causing my cats to go bad, I want to fix that so I don't just blow it again.

And I don't have any other bolt-ons or performance parts. Just a guy that needs his dang car fixed!!!

 

Premature catalyst failure could be caused by a few things:
1) Car is running too rich (which would throw a CEL within a few drive cycles of the ECM realizing it) causing unburnt fuel to actually ignite within the catalyst, clogging it up
2) Could have a bad O2 sensor upstream causing the A/F mixture to be off

Was the 0420 code the only one that was found? The cat definitely needs to be replaced either way. I'd start there and replace the O2 sensors as well (these are a cheap insurance policy) since you're up there in mileage.

 

Yes, the 0420 was the only code coming up, at that time. I am checking it again tonight so we'll see if there is anything else.

I plan on replacing cats and O2 sensors. Will I need to replace all of them, or just precat sensors? Also, is there a precat O2 sensor for bank 1? I can easily see the precat O2 on the front of the engine, but I can't see one on the back. It is quite crammed back there, so maybe I am just missing it. Thanks for your input.

 

There are four sensors. Each bank has a sensor before and after the precats (2 banks x 2 sensors = 4) The sensors before the precats are called air fuel ratio sensors, and the ones after are called O2 sensors. The sensor that you have identified is the air fuel ratio sensor for bank 2. The one at back which is difficult to see is the air fuel ratio for bank 1. But it can be seen you if look well enough, maybe with a torchlight. You could trace it with an imaginary line from right opposite its counterpart on bank 2.

The other two (O2) sensors can easily be seen if you go underneath the car, raised of course.

 

Cats. Since you're over the 80k mile warranty limit, you will have to pay out of pocket.

Your best bet is to do what Cory said, and get the Racingline cats. They are a lot cheaper than OEM cats, and are direct bolt-on replacements. Any competent muffler shop should be able to do the swap for you.

 

I just had a mechanic friend look at the car. Confirmed the bad cats. But as for the noise, it seems it is a bad alternator or belt. Not related to the cats. Whew!!

I've been looking at cats online. Are there any that people recommend other that racingline? I've been looking at Eastern. Any opinions? Thanks all.

Just an update. I called the stealership and apparentley my car is a California based car. Their emissions are only warrantied up to 70k miles. So I asked them for pricing on the cats: $597 for the front, $757 for the rear. I think I will be buying them online.

 

so yes my code shoots out p0420 but i dont have the whining noise or the egg smell just the light check engine light comes on and off and shoots out p0420.... it comes on usually when i'm drivign long distant on the highway aand goes off after a week or 2 when i'm driving normally. when i went to the dealer he said that it was my o2 sensers AND my catyltic converter, but those guys at the dleaership are douches so iono if i shoudl just change my o2 sensors, or chagne botht eh sensors and the catlytic converter.

 

P0420 is bank 1 CAT (firewall side), the wining noise could be because of the low power steering fluid, and I don't know anything about "rotten egg" smell lol. You could get headers and leave the main cat on the exhaust system and weld O2 bungs after the main cat for the down stream O2 sensors, that way you'll keep the CEL light off, but will fail the visual test, then again you may still pass the inspection depending on the shop you go to.

 

Try cleaning the MAF with some carbon clean or seafoam I did this to mine last month and light never came back on I also replaced the air filter pvc valve and put high octane gas the reason why most of these go out is because cheap gas and no servicing lime air filters and tune UPS my car has 180 k and never had to replace the cat also I don't have any cats on my 97 240 and I pass inspection with no problems what I did is I bought o2 symulators for 15 dollas I don't know how it is in other states but in Austin tx they do smog test and yes it passes