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Ok guys.. sorry for the long post but I need to get you all up to speed on my situation

I am new to this forum but am NOT new to forums and know my etiquette. :nerd

I have search and searched and also have my local Vegas FJ Cruiser group help put thought into my situation..

https://www.facebook.com/groups/vegasfjcruisers/

I bought my beautiful 2007 FJ @110k a little over 3 weeks ago, and on the night I was taking her home. I got all CELs lights on ( CEL, traction, VSC, VSC TRAC) :frown

Pulled the codes and was throwing 420 for Catalyst System Efficiency Below Threshold (Bank 1) and 430 for Catalyst System Efficiency Below Threshold (Bank 2)

Long story short...

I got the dealer to replaced BOTH cats (aftermarket) which cost them $1500... got my rig back and drove 31 miles and all the lights came back on...:mad: notified dealer right away..

Mind you, I did manage to put on about 800+ miles before the cats got replaced.
So at that rate, I figured that I've fried the O2 sensors for driving with the bad cats for that long..

Got it back to the dealer ASAP and plug it up and pulled live date to see if the O2s are working properly.. and voltage showed that the O2 operating normal and check the temp in and temp out of the cats... everything looked normal even with the CELs on.

They took my FJ back to the Performance Muffler shop to have them look into it and they reported back that the O2s were responding slowly... What ever it is, they replaced the 2 rear O2s...

Fast forward... They even comp me a full detail inside and out for my inconvenience; being confident that they have resolved the issue..

Drove the car pass 35 miles and now I'm thinking that I'm good and clear...

BUT NO, at 41.1 miles... CELs all back on... :flame:

I understand through search, theres a good handful of people that say that throw these code fairly frequently... but still; it isn't right...

I'm going to have them give me some fresh plugs... mind as well tell them to give me a new gas cap as well.....

So I suppose they should look for an exhaust leak too right ?! do you guys think I could milk them for a new Exhaust system ? haha...:angel
What else could it be ???

Nevada does not have a USED Car lemon law but is still pretty much obligated to make it right under Nevada statutes.

What do you all suggest? Again sorry for the long post but TIA for any input you may have...

Kenny
 

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I think aftermarket cats might be the problem.
 

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1. No way more than 1 cat fails simultaneously.
2. No way more than 1 OX2 sensor fails simultaneously.
3. Highly (very highly) doubt a cat an OX2 sensor fail simultaneously.
4. Obviously the prior owner or the dealer cleared all codes to an existing issue. When a hard fault code is logged, the component being replaced should be properly diagnosed and confirmed for failure before replacement. Obviously, some system controls are difficult to check and have to be replace to confirm root cause, but this would be limited to the ECM and other sub controllers, if you are not the dealer. The dealer shold have ECM diagnostic capability.
 

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You mentioned an exhaust leak. One thing that can fool your PCM into setting CAT efficiency codes is an exhaust leak. The leak can be very small and you may not know it's leaking at all. A smoke machine is the best way to detect a leak like this.

Has anyone looked at the fuel trims? This will tell the tale on how your engine is running. A good running engine will have a ZERO long term fuel trim but anything + or - 10% is acceptable.

If everything checks out I would zero in on the aftermarket CATS. There are good and bad ones out there.
 

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What are your fuel trims running. Both long term and short term. These are listed as LTFT and STFT the dealership must have looked at these. The reason CATS go bad is because they get overworked from the engine running to rich. Surely there were more codes. Good post Jimmiee
 

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Are the new codes exactly the same?

My thoughts on possible existing issues would be

-MAF, may beed to be cleaned or replaced
-Front O2s, the "difference" the ECU is looking for is the change between front and rear values, if the fronts are sending a incorrect starting value then the cats wouldn't be able to clean to the point the ECU is expecting to see at the rear sensor values
-New Cats, could be that they are too high flowing and not cleaning the exhaust as mych as the ECU is programmed to see at the rear O2.

But these are all guesses without knowing the exact new codes
 
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