Hi

I wanted to find out if the catalytic converters on a 2003 S-type, 3.0 can be cut, replaced and have new ones welded on?? I keep getting conflicting advise.

I have a mechanic that wants to clean out the ones that are their and just leave them hollow. I am not comfortable with that. I live in FL so there are no emissions test done her, but I still would prefer to replace them.

If they can be replaced without having to buy the entire exhaust down-pipe, could someone please recommend where to get them??

Your help is appreciated.

 

yes you can weald new ones in , and they do not need to be oem ,
i fitted magna flow 59956 200cell cats to mine . magna flow have many options .
check there website . size matters as there is limited space to work with .

 

Time to find a new mechanic!

Don't hollow out the cats. On 2003+ cars, the downstream O2 sensors have two functions. They monitor catalyst efficiency AND provide feedback to fine tune the fuel/air ratio. If the cats are hollow, the trim signal will be wildly inaccurate. Performance and driveability may suffer.

For 49-state cars, Davico offers replacements that are only about $180 each on RockAuto. That is a complete downpipe assembly. No personal experience with this brand, but when I need to replace mine, I plan to go this route. Amazon even carries Davico. Look up the numbers on RockAuto and then compare with Amazon.

About 7 years ago, I had to replace both cats. At the time, the aftermarket options didn't exist. Any universal fit cats were too big for the tight confines. Midas cut open both cats and had them rebuilt locally. Not cheap, but still substantially less than new OEM, which was about the only other option at the time.

By the way, what fault codes are you getting? If P0420 or P0421 (converter efficiency below threshold), the fix may be as simple as new upstream O2 sensors.

 

rockauto has the complete cat for 179 per side. just put them on mine a few weeks ago and they work well

 

Groovy! Did you install them yourself or have a shop do the work?

I'm especially curious about the connection at the aft end. The product description says it is a slip fit. Was there enough slack for ease of assembly, while still being tight enough to prevent leaks? Or was it necessary to weld the connection?

 

I did do them in the driveway...but.... you will definitely need a torch to get the manifold nuts off without breaking the studs. At the rear they are a slip fit but you will probably need a torch again to heat them up and get them apart. Going together is tight but they do make it if your patience holds up. A good time for an oil change as the drivers side goes easier with the oil filter off. Passenger side is pretty easy in and out. Not a bad job with a little help from the heat. No leaks and the ECM doesn't mind them at all like some of the high flow cats.

 

Thank you everybody for your input, I really appreciate it. I purchased a pair of Walker 93251's and will have someone install them. I hope it goes well!

 

Turns out it was a defective MAF sensor, I had installed recently!! Saved a ton of money!!

 

Great news! For future reference, what were the fault codes or symptoms pointing towards the cats? And how did you diagnose the MAF sensor instead?

 

A friend of mine who is a mechanic finally had some time to look at the car and noticed a hairline crack in the "new" sensor. He recently retired from being a mechanic. The codes I was getting are: P1074, P1674. It also showed misfires in cylinder 3 and 5, I believe.

Changed 02 sensors sensor (upstream), had a tune-up, put in a new fuel filter. The tune-up was due anyway, since I have 101,000 miles on the car.

The only problem I now have is I keep getting restricted performance and check engine light keeps coming up after clearing out codes. . The car is running perfectly well again, no more exhaust fumes, loss of acceleration, rattling catalytic converter, etc.

Do you think I need to the clear codes by disconnecting the battery??

 

No. It's still not fixed.

Stop clearing codes (what are they now?) and fix the car

 

Go to the stickies and get yourself a copy of the JTIS then read the codes and check what you have to do to repair the car