I have a 2002 X Type 2.5 with 69000 miles. As a result of the all too common intake manifold gasket issue it had a tendency to misfire on cold mornings for a brief period (blinking check engine light). After installing new gaskets that problem was resolved. Unfortunately, I began to get OBD 2 Code 430: Low Catalyst Flow, Bank 2, the bank just behind the radiator. I discovered that I was lucky, because it requires only three hours of labor to remove and replace this cat not to mention at least $350 of expense to buy a new after market cat from Rock Auto, I don't want to think what a dealer would charge!!

THE REAR CAT REQUIRES SIX HOURS OF LABOR: You have to remove the sub fame and transfer case!!!! According to All Data you need a special fixture to hold the engine in place while removing the sub frame.

I first tried a product called Cataclean marketed by Pep Boys which cost $25.00 per 16 ounce bottle and boasts 50% success. I believe it's lacquer thinner because it smells just like it. There are numerous posts on the net about using lacquer thinner to clean clogged cats but there are mixed reviews about the results. I did notice that car ran better after trying a bottle of Cataclean. It's super strong solvent that cleans injectors and valves. Unfortunately, the dreaded CEL came back with same code 430.

Undaunted, I tired another remedy, A few years ago, I eliminated the cat on a car I had and to keep the CEL light off, I used an 18mm spark plug de-fouler, from the Help Rack at Autozone. You have to use the 18mm size because it's the same thread size as an 02 Sensor. You get two in a pack for $5.00. Use a 1/2 inch drill to enlarge the inside diameter of one so the 02 sensor will fit inside, Then insert the sensor into it then put the unmodified one on the end. Then screw the sensor in with these spacers so the sensor does not protude so far into the cat.

The rear sensor has no impact on driveability it merely monitors the performance of the cat. If the cat has been subjected to a misfire and raw fuel is dumped in it's quite possible that some of the palladium or other catalyzing metal was burnt off thus reducing the effectiveness of the cat so the rear sensor reads excessive flow and triggers the light. The car is still most likely complaint but it falls below the parameters that trigger the CEL. By moving the 02 Sensor out of the direct flow of gases passing through the cat whilst still having it sample a little it will report a reduction in flow to the ECU and keep the CEL from illuminating.

This simple procedure can not harm your engine because the rear 02 Sensor only monitors the performance of the cat. The only down side is possibly failing an emission test if you live in a locale where they are administered but it's quite possible that there will be enough residual function of the cat to pass the test.

This simple procedure can save you hundreds of dollars and the aggravation of hours in the garage on your back trying to separate heat fused exhaust components and thousands if you go to the dealer. Especially if you have to replace the bank one cat.

These Jaguar Cats are especially vulnerable to this destruction because they are bolted directed below the exhaust manifold so any raw fuel will drop right in as opposed to other cats that are mounted more aft.

 

I did the same thing. I had code p0420 and p0430 (both cats) I tried Cataclean first and it made 1 light go out temporarily, but it later came back on.

I used a pre drilled de-fouler I found online after both cats and the cel hasn't came on since for those codes.

I would only recommend this method if you are not experiencing any symptoms of a bad cat converter. My car ran very well, so I had no problem using this.

If you have a clogged cat converter and your car is running bad, you should really fix it the right way.

 

You are right if the cat is plugged this will not work however if the cat is plugged you will most likely have performance issues even misfires caused by back pressure. A cat can fail by clogging up, usually related to age and excessive oil consumption or it can "burn out" i.e some of he catylizing mateirial is burned away rendering the cat less efficient yet still functional. Sometimes a clogged cat can be cleaned by removing it and soaking it overnight in soapy water but it the honeycomb material inside appears to be melted and constricted it wont help.

Because of the design or the Ford Motor the Jag Cat is mostly likely to burn out was clogged up because of its vertical orientation and close proximity to the exhaust manifold. Now I understand why there are no after-market headers available for these cars it's impossible to fabricate them.

 

ive recommended O2 Simulator, mini catalytic Converter cel fix for years for this issue and works everytime as long as cats are not plugged. Theyll even work if empty