I have high flow cats. Is it possible for a bad cat to fall apart and particles get sucked back up into the engine and mix with your oil leading to score the engine internals.
A p0420 code popped last week. "Catalyst System Efficiency Below Threshold (Bank 1)" I cleared it but it same code came back.
Bank 1 is the passenger side right?
I've had this car for about 6 months this my second oil change. The first one I didn't do. This time and previous time I noticed the oil very black. I can assure this time that only 2500 miles and the oil is very dark in my opinion.

Well i am at this very moment removing my cats and installing my test pipes. Also, there are two O2 sensors on each cat, only 1 available on my test pipes. What to do?

Any tips on en engine flush would be great too.

Thank guys.

 

Cats could be breaking apart, could also be that the HFC are flowing so much that the sensors think their not working. No this wont lead to engine failure. Black engine oil is normal near the end of its life. How many miles are on the oil? What kind of oil?

 

2500 miles on the oil. 65 miles after oil change. 0w-40 Mobile 1.

 

65 miles after doing an oil change its jet black? Ya thats wierd.

 

No no. After 2500 miles its jet black. I'm about to drain my oil right now after 65 miles to check it out. Will keep you posted.

do you know what O2 sensor off my HFC goes into my test pipes, the lower or upper? And what do I do with the remaining 2?

 

Black means it's doing it's job and has nothing to do with life remaining. You should be concerned if it doesn't come out black after the first 1000 miles. Better oil turns black faster.

 

Thank you. And as far as my p0420 code is concerned?

 

If your test pipes don't have enough bungs for the sensors you got ripped off on ebay . Either get the correct amount of bungs welded in or get a decent set with the correct bungs. If you don't install all 4 of the sensors you will have check engine lights.

I have never heard of exhaust sucking anything up before!?!

 

Exhaust works one way - OUT.

Bank #1 is the same side as cylinder #1.

Black motor oil is good. It shows that the oil is doing what it is supposed to do.

Motor oil will not fix Catalyst System Efficiency Below Threshold.

 

If you're running with a clogged cat you could cause extra wear and blow by due to the increased pressure in the cylinders. Highly unlikely anything was 'sucked' into the engine though, since gravity and physics works.

 

My mistake, all 4 bungs are there. Is there a way to hook up a volt meter to these O2 sensors to check for proper readings. Just wondering if its my cat or O2 sensor then.

 

http://www.blackstone-labs.com/

If you are worried about the condition of your oil. ~$30 bucks will get you an analysis with their writeup and interpretation.

I think you oil is fine, personally. Just a bad cat that may need to be replaced or a sensor thats dead.

 

I've heard from the dealer service manager at Coffey Nissan that it is possible for particles from the HFC to be sucked into the engine. This guy wasnt an idiot and said that back preasure can suck it in or whatever.
OP where did you get your info? It might just be Nissan propaganda...

 

Google ma'man...

I was reading some other forums, but then came across that it was possibly due to the cat being designed too close to the head, I dont know if on a 350z this can happen.

Now it's got me on a CC breathing trip. Is it my lack of vent in my crankcase causing my oil to darken so fast or some BS with my cat. All I know is if my cat material is getting into my oil, could seriously hurt my engine. Which is built so i'm taking every precaution.


This could be the ticket... Thanks Can an oil analysis define if it is simply blow by past the piston rings, (water vapor, hydrocarbons, fuel, etc) OR pinpoint that it's cat material? I guess so right?

I scratched intsallin my test pipes btw, this would only compound my discovering the cause.

 

The cause of exactly what? The code? You seem to have left out what you're looking for providing only speculation...like the scored cylinder walls... how do you know that?

Are you consuming oil at an alarming rate or something?

Taking it to the dealer with any mods is instant FIAL. They will find any mod they can to deny your warranty, which is usually complete BS. But if you have a clogged cat you are probably doing some damage to your engine. I would get test pipes ASAP.

Blackstone will tell you if something is in your oil that shouldn't be. I recommend everyone do it at least every other oil change.

 

You might consider getting new catalytic converters since test pipe will be an automatic fail when you get your emission test.

 

Yes the code. And no I don't think anything is scored, just came across some info that if cat material gets back into your engine from backpressure it could lead to that.

I cleared the code today hasnt popped back yet, but probably will. Most likely a bad cat. If it was clogged I would feel it. Thanks for the input guys.

 

Get TP's... I did! I used to have HFC.

 

I will say that I have seen first hand a cat come apart and a piece get sucked back into the engine and damage a piston. In was on a Z3 and the piece of the cat was found in the cylinder.