My jag is a 2003 model and it has 66500 miles...now showing the P420 code. Is this covered by the 8 year/ 80000 mile warranty?

 

That warranty starts at the original in service dates so you are probally beyond that time.

 

Get one of these and kiss that P0420 good bye!


Works great--as long as you don't have to pass a tail pipe sniff test!

 

Alright, now you have to tell us where & how

 

You can get it from the Amazon link I posted. All it is a spacer for the downstream O2 sensors. You remove the O2 sensor, screw in the spacer then screw the O2 sensor into the spacer. It spaces the downstream O2 sensor(s) out of the exhaust stream and this corrects the reading from the sensor to the ECM. The "tuners" who remove their cats in there exahusts use them all the time. I got fed up with the P0420 code and put one in at bank 2 and it fixed my problem--BTW I tiried a new O2 sensor 1st--it did not fix the problem. The only function of the downstrem O2 sensors is to check if the cats are working. Using a spacer will not affect anthing else. As I said, if you have to pass a tail pipe/sniff smog test you may/will still fail. $20 for a spacer or $1500 for a new Jag cat....you do the math!

 

To answer your question - no, this would not be covered.

Before looking at a replacement you need to find the root cause of the P0420 - it might not necessarily mean your cat has failed. Perform a P0420 search on the forum and happy reading.

Two causes that come to mind is a failed O2 sensor or an intermitient misfiring coil(s)

If you go down the route of replacing the cat converter try to source one from a wrecking yard if possible.

Good Luck

 

I would think if the cause of the P0420 was a misfiring coil there would be misfire codes set. As I said, replacing the O2 sensor did not fix my problem either--and I had no cylinder misfire codes. I can assure you the spacer will get rid of the P0420. If you are having cylinder misfires you should get codes for them--even if you use the spacer.

 

Sometimes the coil misfires are so intermitient the PCM doesn't flag them. It has happened to me (never had any OBD codes) but after testing each coil at idle I found an intermitient misfiring coil - I agree on the spacer getting rid of the P0420 but that would be essentially putting a "band aid" on a wound... To add... the OP is in NY (more than likely that vehicle is going to go through a smog test) so adding the spacer is "game over" in this instance...

 

Well, this morning when I started the car and checked the codes...the P0420 was gone and a misfire code showed up...P0305... Cylinder 5....I had this replaced about 6 months ago...

 

First, when you replaced the coil in Cyl 5 - was there any oil residue on the coil - if so, then you should have changed the cam cover and spark well gaskets on that side - oil intrusion into the spark well kills ignition coils FAST!

Second - what brand coil did you replace with? OEM or aftermarket - if the latter - they just don't produce quality coils via aftermarket.

Either way, take care of that coil on Cyl 5 and count your blessings that that coil didn't toast your cat converter.

Take care of this ASAP - do not drive your car with a misfiring coil - as I mentioned in my last post - sometimes the misfires are not picked up by the OBD - but I guess the misfiring is at a point where the OBD finally flagged it.

Last thought - when was the last time your battery was replaced?

Just my $0.02

 

Any recommendation on a quality replacement Coil? There's like 4 of them on RockAuto. All different manufacturers. Who Manufactured the original OEM Coil?

 

O2 Extender Oxygen Sensor Spacer HHO Test Pipe 1 Bung | eBay