hey guys, a few months back I changed all of my o2 sensors and cleared the code and it has not came back on until the other day. It was off for about 3-4 months. Would replacing the cat be the next step? I clear the code but it comes on after a few hours of driving. Some advice please, and cost and labor cost as well too. thanks guys.

Sounds like the cat is bad. OEM cats are expensive, I would look to something universal.

what do you think about the eastern cat? its about 200 bucks. And would you think the check engine light would go away once installed? Heard from mechanics that unless its oem the light would stay on.

If it's an adequate cat then it'll work. Various people have posted the non-OE ones they've used. Your mechanics are wrong.

edit: and I meant to say: which is good as it saves money

I agree with JagV8 - your mechanic is dead wrong. There are a few options that are direct fit replacements. I believe Eastern is one option.

Before changing the cat can you swap the after cat O2 sensors from side to side? This will make sure you don't have an O2 problem. If the same code comes back then it's not the O2 sensor.

Don't want you to change a cat and still have the same problem.
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Leave the factory cats on and(ill say it again) go to O2 Simulator, mini catalytic Converter cel fix and buy the angled downstream 02 sensor extenders for the stype exhaust they're $30ea. Odb2 codes do not "magically" go away. They have to be cleared after repaired. Thats not to say that after so many key cycles a cel wont shut off, but the code stays. Iam not a fan of aftermarket cats unless youre selling the car. Reason, when i scap cats, oem fetch $40-80each from a cat recycler. Aftermarkets get $5! When i asked why. "they have very little precious metal in them and not worth much" and its the precious metals like paladiium etc that cleans the exhaust. So even though it may last a yr or more, they dont last long afterwards. Thats why most only have a 1yr warr. I have occassionally seen and bought stype oem cats for $500 on the web from differant sources, but no one that has them constantly at the price. So theres you some more info

thanks brutal. so are you saving if I have this o2 simulator installed my problem will go away? and then I just clear the code with the scanner? I dont have to do anything else? and what would labor cost on installing the simulator. thanks again.

Yes its a "test" piece to see if the sensor sees cleaner air when installed. If you leave it installed well thats your choice. Stypes are pretty easy to install. You only need a 22mm wrench, may need a 02 sensor tool if rusty. Put the car up on kackstands ,remove downstream 02's and install spacer and reinstall 02. Clear the code and thats it

I have been following this thread closely - have a S-type 2002 as well with the P0430 code. Have changed O2 sensors/new coils, plugs - code returned, used a bottle of Guaranteed to Pass Emission and RXS right before inspection almost two years ago and passed inspection. CELs been back, have been thinking of installing O2 simulator as well. Only question that I have as well - does anyone know if the inspection guy looks underneath the car for modifications with a hand mirror or is it something else (NJ) they are looking for ? If not I would go with Brutal's suggestion in a hurry .

so I am guessing I would need 2 of these simulators? not just 1 even tho I have the code for 1 cat?

I would do both while youre there. I do

I do really appreciate that info, it will save me alot of money. Just wanted to know if my cat was really in bad shop tho would these simulators make a difference at all? All it is doing is just making your cel go away, and not actually helping a malfunctioning cat?

if you cat is plugged or coming apart. NO they wont fix a broken/bad cat. only ones below EPA mandated efficiency for cleaning exhaust. This could easily outlast your ownership of the car

I have been experiencing an O2 P0420 off and on several times over the past year and had it on my list of things to do and now I have more info to tackle the problem. Thanks again Brutal!

sjgh - NJ looks under the vehicle with both a mirror going down both sides and a ground level camera and monitor - this will be easily picked up...

gotta say its been 2 days of driving with these o2 simulators installed and the check engine light has not turned on yet. Hopefully it will remain off

Last year my Jag was tossing the P0420 but the car ran fine so we reset the computer before taking it in for emissions. This year emissions caught it, Utah has changed the laws in 2013. Anyway Master Muffler wanted $1800 to remove and replace just the passenger side catalytic converter. He said it was a dealership part only even tho he had magnaflow equipment on display. I checked and magnaflow does make one to fit jags but it requires being fitted. Midas wanted to run expensive diagnostics blah blah blah. I was set to park it in the garage and just use the van. But luck would have it that I found an up and coming local mechanic shop and they not only put in a nice aftermarket unit but replaced the thermostat & seal, the orings on the fuel injectors, and washed her up to boot. Total bill $708. So you see guys it does pay to shop around!

It would take a pretty sharp inspector to notice the O2 extenders!!

There are so many variations in O2 placement and the Jag is not a common car, so they won't know what to look for. I would bet money that they won't say anything at all.
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lol. Old thread yes but I had to reply- the entenders ere easily spotted. No cars come with them. Theyre meant for spark plugs (or cheating emissions testing). The testing station will see it. And hopefully you wont get a massive fine for altering the smog devices. Some smog dudes take their jobs seriously. Others will smog test another car in yours place for a small fee. Damhik