Replacing the cats

M

moondawg1951

Member
Location
Broken Arrow
Car
Fx35
Name
Kirk
Having to replace both converters on my 2006 FX35. Car started rough idle while driving one day, so I drove to shop I use for repairs ( about 10 miles. ) They told me the right bank of coil packs were not firing, and left side was on the way out also, so had all 6 replaced. Next day I got P 0420 code. After further analysis, I was told right converter was bad and left was on the verge of going out. They said probably from all the raw fuel in the engine that was ignited in the converters during the 10 mile drive. Also told me these converters are very sensitive and doesn't take much to throw a code. Talking to the mechanic, I told him I used 87 octane fuel that has 10% ethanol. Asked if he thought that might have contributed to the damage. The manual says it's acceptable to run that, I was wondering what other people on the forum run in their vehicles, and thoughts to the damage to the converters..By the way, car only has 66,000 miles on it. Thanks for any info..
 
It's really not that much more expensive for 93, and some members here have reported better mpg with it. I guess it depends how often you drive, but let's say 93 is 30 cents more, and you fill up 20 gals twice a month. So each fill up you'd pay $6 more, $12 a month, $144 a year.

As far as the cats going bad, I guess it's possible with the coil pack issues. You might consider high flow cats or something aftermarket given how expensive cats are, with OEM probably being marked up. I thought it was interesting that they are saying the coil packs are on their way out, I would think they either are working or have failed, but you can't tell any in between. Same with the cats, although they might have visually inspected them.
 
Too late for skipping the cats..Already purchased them. These days it's really hard to find a shop you can really trust. Hopefully these guys are being straight up with me. They were given a good name by several friends.
 
10 miles running rich isn't going to kill your cats, it takes a lot more than that. The mere fact that the shop replaced an entire bank of coils and then the other bank makes them suspicious. It's highly unlikely that an entire bank of coils fails at the same time, they typically fail individually. And for them to say that the left side was on it's way out so you should replace them is total BS. A coil pretty much works until it doesn't; toward the end, it will start failing intermittently but you can't say "oh that side's on it's way out, better replace those too". If an entire bank went out, your car wouldn't run. Even one coil going out causes your car to run horribly.

A decent shop would identify which coils were actually causing misfires and just replace those. And now this shop is saying that one cat is shot and the other one is going is ridiculous. P0420 is the code for the passenger side converter so maybe it's bad. But if you're not throwing a P0430 code for the driver's side cat, why would the shop recommend you replace it? And before just replacing the cat, I'd clear the code and drive around to see if it comes back on. It may have just been because of your misfires.

87 octane gas didn't cause your problems. The FX can run it, but you'll get slightly lower mileage and lower power because the knock sensor will be kicking in all the time and pulling timing.
 
+1 Agree with everything Shadow said above. As for the gas, personally...I have only run 91 or 93 in my FX in the six years I have owned it.
 
It was the dealer that replaced the coils. They replaced a ground strap also. They said the ground was corroded, so it lost it's effectiveness causing the coils to overheat and fail. True or not...who knows....This is another shop that diagnosed the cat problems, although the dealer told me they might be affected because of driving it while it was misfiring. I went back to the dealer and they cleared the code, but came back on the next day. That is when I took it to the shop that said the cats were bad.
 
Couple years ago.. Stealership told me my rear left and right bearings were shot because my right rear axle was making a clicking noise. So they wanted to fool me and replace the bearings and silently lube the rear axle click noise and eliminate the sound hence pointing the bearing change fixed it. I told then to F off and pointed out what they were doing. Never go to a stealership never!
 


You could've also grabbed some low mileage used 350z/g35 vq35de let cats off there forums. Seeing as the g35/350 guys are more into modding there cars, their cats are often for sale. Failing coils should have thrown more than one code.. A cheap code reading can be purchased as a tool to help you avoid fixing more than needed.

Bring it back to the dealer and see what they say as they're the ones that replaced the coils... Your car has 66k and I believe the cats are warranted to 8yr/80k? Don't quote me on that.
 
Thanks Shadow. I just got the P0430 code last week and have to check it out further. Some internet search gave a long list of possible culprits for my P0430. Is that code usually directed straight to the cat?


Dracula said:
Couple years ago.. Stealership told me my rear left and right bearings were shot because my right rear axle was making a clicking noise. So they wanted to fool me and replace the bearings and silently lube the rear axle click noise and eliminate the sound hence pointing the bearing change fixed it. I told then to F off and pointed out what they were doing. Never go to a stealership never!
Click to expand...

Can I guess? Glendale or Van Nuys?
Try Cheryl at Monrovia. I have yet to catch anyone there in a lie.
 
I have an 09 and my ses light came on I did the pedal dance and it is 0420 anyone knows what it is I checked and im pretty sure its the cats but I hope not!

---------- Post added at 10:27 PM ---------- Previous post was at 10:16 PM ----------

Also I recently got in an accident I got rear ended so dont know if that would effect anything. And I cleared the code I dont know if thats ok im just hoping it doesnt come back lol
 
porkandbeans said:
Thanks Shadow. I just got the P0430 code last week and have to check it out further. Some internet search gave a long list of possible culprits for my P0430. Is that code usually directed straight to the cat?




Can I guess? Glendale or Van Nuys?
Try Cheryl at Monrovia. I have yet to catch anyone there in a lie.
Click to expand...

i bought my car at metro infiniti and i always went to cheryl for service. i am closer to glendale and i recognized steven but hes at van nuys now.


Sent from my iPhone
 
moondawg1951 said:
It was the dealer that replaced the coils. They replaced a ground strap also. They said the ground was corroded, so it lost it's effectiveness causing the coils to overheat and fail. True or not...who knows....This is another shop that diagnosed the cat problems, although the dealer told me they might be affected because of driving it while it was misfiring. I went back to the dealer and they cleared the code, but came back on the next day. That is when I took it to the shop that said the cats were bad.
Click to expand...


I have had the same issue happen to my FX. Burned a coil cylinder 1, replaced it. Burned the same coil and replaced again. The third time i burned coils 1,3 and 5. All the passenger side coils. Started doing some research on this and came to figure out there is a TSB (Service Bulletin) from Infiniti that addresses this problem and it does have to do with three grounding positions.

You have to remove and replace the negative battery cable x1 (part #24083-CG000) the engine ground cable x1 (part #24080-AL510) the ignition coils AND ONLY the ignition coils that are burned (part #22448-AL61C) and the ground bolts x5 (part #01456-00031) There is another ground bolt inside the cab that needs to be replaced as well. It is behind the glove compartment. Due to the coils misfiring i then got a code for my cat. What happens is your fuel basically starts dumping into your cats. I will have to replace the passenger side cat. I drove my FX with the cylinder 1 misfire for a while. Like a month. Driving it 10 miles won't ruin your cat. Find a new mechanic.
 
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