Chrysler 300C & SRT8 Forums banner
1 - 12 of 12 Posts

·
Registered
Joined
·
228 Posts
Discussion Starter · #1 ·
Hi guys, I recently purchased a 2006 Chrysler 300C SRT8 with 190,000KM (118,000miles)
I kept getting low efficiency check engine light for the right Catalytic Converter, so I bought new ones.

Here is some pics of my old ones.

Now why would one cat be destroyed that bad?
Is the same going to happen again?
As far as I know my engine is running very good at this point with no miss fire or anything like that. No check engine light on.

Any ways I just wanted to show my old cat.

The car sounds and drives better now.

Btw I installed OEM cats in.
 

Attachments

·
Premium Member
Joined
·
829 Posts
Do you know if the previous owner had a supercharger on the car? I ask because that is one of the biggest reasons that I've seen that kills cats on our cars. The OEM cats are built to last 100K+ for warranty purposes and you're at 118K, so it may just be that they are failing naturally.

Heat is the biggest killer of them.
 

·
Registered
Joined
·
228 Posts
Discussion Starter · #3 ·
Thx for the reply, I bought the car from an auction, the car is 100% stock. I cant see anything been done to it, not even cold air intake or even exhaust mod.

Even tho that the cats are built to last 100k, why only one cat completly gone and the other was still look new from the inside?
 

·
Registered
Joined
·
34 Posts
Its possible the car had, or has, ignition problems on one side, dumping unburnt fuel into the cat where it gets lit by the hot honeycomb. I havent seen it on an SRT8, but i have seen it on a great deal many other vehicles. Are the o2 sensors good looking? Do the ones on the bad cat side look like they have been replaced? At 100k, SRT8s needs new plugs too. Since there is a decent chance they need to be replaced anyway, pull the ones from the bad cat side and see how they look. :raincloud
 

·
Registered
Joined
·
228 Posts
Discussion Starter · #5 ·
That make sense, I’m going to pull all the plugs out and see how they look.

My O2s look clean.

Now how sensitive is the SRT8 computer to recognize misfire or too much fuel?

I’ve seen Ford trucks misfire with no check engine light.


Thank you guys for the reply
 

·
Premium Member
Joined
·
829 Posts
The SRT8's are very sensitive to recognize a misfire and will usually log a code. Do the key dance (on-acc-on-acc-on) and see if any codes are stored (will show where mileage is). If it was an old problem and cleared, there may be no stored code.
 

·
Registered
Joined
·
228 Posts
Discussion Starter · #7 ·
Ok that good to hear. I have access to a $4000 snap on scaner and there is no codes. I have a new dealer installed and flashed PCM and brand new mopar throttle body.

I want to pull the plugs out but been lazy.

And btw the key dance never worked on my 2006 300 Touring, my 2008 300 limited or this 2006 SRT.

It used to work on my 2002 300M Special, and my parents 2001 Dodge grandcaravan sport.
 

·
Registered
Joined
·
7 Posts
I've been fighting a P420 code for ~3 months and am going to drop the midpipe next week. Will be interesting to see how it looks. Ordered a flowmaster midpipe/cat to replace it.

Car is an 06 SRT8 and has ~42,000 miles.

Only other vehicle I have ever owned that lost a cat was my 95 Dodge truck. Maybe it's just something special about Chrysler products...
 

·
Premium Member
Joined
·
4,470 Posts
I just had to replace the driver's side cat on the MSRT8 at 79k miles and less than two years after install of the Edlebrock eForce supercharger. I would get a very infrequent O2 code that I didn't pay much attention to until recently when it began happening more frequently. When the tech checked it out (while we were in New England with the new 300C Platinum) I was told it was the A Bank Cat and it would need to be replaced. I don't know why an SC would cause a problem with the Cat other than it stuffs more air in the cylinder (and more fuel to go with that)... but I've had no codes for misfire, etc., so I don't think I was dumping fuel into one side or a specific cylinder.

Also don't have any pictures of the Cat. Just the dealer's work for it (which I trust).
 

·
Premium Member
Joined
·
4,515 Posts
Totally agree with you most of those OEM kitties are designed to last 100K + for assurance reasons and you're at 118K, so it may just be that they are unable normally.
Original post is 4 years old bud... Someone else over posted.

Cats on LX vehicles have been know to fall apart well before 100k, it happens.
 
1 - 12 of 12 Posts
Top