Bad news - cat converter down on my 360 :(

Not sure what year is your 360. Emission items are covered for 8-10 years under warranty in some states such as CA.

 

If it's a 2000 360 and you're messin' with main cats, you might be well advised to have your tech CAREFULLY inspect the condition of your pre-cats (in the exhaust manifolds). When they fail (not "if" they fail), you'll be riding in that Infiniti for a whole lot longer than you expected.

 

Would it be advisable or even technically permitable to remove the pre-cats from the manifolds as a precaution? This whole "pre-cat particles getting sucked into the engine" stuff gives me the jitters.

 

I know of a couple of 360 owners who have removed these POC precats. You can either have an independent shop cut them out of your headers (requires removal and discarding of heat shielding) and jet coating the pipes, or have a set of aftermarket headers installed. There seems to be varying success as to whether or not you will get check engine codes after you are done.


Lou

 

If the light is being set by an inefficent cat it will take a long drive cycle to reset. I have had cars take a couple of hundred miles to set the cat monitor. Do you really want them to do that much driving? As a shop owner I would never dream of our guys driving a 360 long enough to reset a cat monitor. Really dumb on their part. Makes me wonder if they even know how long it can take.

 

You should install an Larini cats! Just cut the problem from the roots

 

The cats are a Federal warranty item so they're not really doing you any favors. Have the car flat bedded next time. AAA covers 100 miles if you have the plus service or just shop around with the tow guys.

 

first...I know nothing about the "code reader" devices used on cars....but are the codes not time/date stamped and saved? If you know the time/date when the CEL triggered, shouldn't the shop be able to determine which code is triggered it? If there were multiple simultaneous codes, those same multiple codes will likely trigger again the next time the CEL triggers. Does that make any sense, or am missing something?

 

Just an observation:
Looking and comparing the "before versus after" O2 readings at various operating conditions such as rpm, load, and operating temperature allows one to evaluate
the efficiency of a three-way catalytic converter.
Given your comment that the check engine warning light would come on after a refuel, you have to take into account that the cat efficiency test runs while you are
driving, and requires a system restart to turn the light on. As a side note, fuel quality and/or composition is a common cause of this fault code.

 

Nope.

 

Almost impossible. You would very probably need to monitor it constantly, real time for 100 hours to do that.

 

The cat is very close to $5000. It is true they need to confirm it but that can take many miles and drive cycles. Just not cost effective for shop personel to do it and no one in their right mind wants that liability.

 

If the core is intact, not cracked and not rattling around inside, no problem. It really is a standard way to diagnose and confirm a bad cat. Many check engine light problems are that way especially a cat problem. The drive cycle length is very unpredictable and beyond that the exact circumstances where the computer senses a fault are completely unpredictable. We all want it to be a one stop fix but sometimes that is just not practical.

Thank your legislaters and environmentalist extremeists. They have the same monitoring system world wide but the degree of sensitivity is very, very, reduced.

 

"Thank your legislaters and environmentalist extremeists. They have the same monitoring system world wide but the degree of sensitivity is very, very, reduced"

So does a US market 360 differ from those supplied to other markets in this respect.

Would a euro 360 have a less sensitive emissions system?

I'd like to own a 360 one day but all this talk of failed headers/cats etc makes me think a should stick with 308's.

 

Catastrophic malfunction? Most likely not. Checking my 1999 F550 owners manual - it states to be careful of a blinking SLOW DOWN light. Usually, in 1996 and newer OBD II cars, it is the CEL or MIL - Malfunction Indicator Light that goes blinking. Nevertheless - this problem is usually caused by a misfire. The OBD II system counts misfires (by measuring the degradation in amplitude between cylinder firings - amazing stuff, eh?) and when a certain number of misfires are captured out of so many rpm's it sets the lights blinking. DO NOT drive under these conditions - you may melt the cats substrate. Then its the old potato in the exhaust pipe routine.

Thinking about this - did you say it happens after fill up? There is a purge vent system that empties the gas fumes from the gas tank. IF, and this is a big IF, if the tank is so full and the system actuates (about 25 mph) and instead of fumes it gets a slug of solid fuel - that could cause the symptoms you are experiencing.

Just a thot

Keep me posted and good luck.

DOUG

 

The OBD system and the slow down lights are completely independant of each other. OBD's ability to see misfires has no connection to illuminating the slow down light. While it is true misfires can and do cause slow down lights I would be very reluctant to say it is the usual cause.

Forget about melting and clogging a cat, Can you say FIRE? Car burned to the ground? That is what is at risk.

 

Were the cats ever updated during the 360's run? I ask because you first asked what year the car is...if they were updated, is the updated cat more durable (sometimes updates turn out to be not much better than the original item...)

Thanks-
Andrew