Does anyone know the part number for the O2 sensor that generates P0420 if it's malfunctioning? I believe it's the O2 sensor that plugs into the bank 1 cat, but I can't seem to find the part number for that anywhere...

 

I'll leave diagnostics to the F-Type owners but here's the part numbers for the US specification sensors. Three for NAS market but only two listed for RoW (Rest of the World) markets:






Graham

 

One note on that code below. Just note it could still have the code after is changed if the Cat is bad...P0420 JAGUAR - Catalyst System Efficiency Below Threshold Bank 1 "As the code description implies the P0420 code means that the vehicle's control module has detected that the three-way catalytic converter is not working properly (is not as efficient as the factory is expecting). Replacing the oxygen (O2) sensors may sometimes fix the code, but in most cases the catalytic converter may need to be replaced to fix the problem. If the P0420 code is combined with other codes, try fixing the other codes first."

Efficiency is likely going to be detected in the post cat 02 (s) . I have attached the part numbers for the various O2 sensor once you determine which one is bad (likely Bank1 from your code) you have all the part#s).

Good luck

DC

 

Just want to update a little here for future reference.

After tapping the cat a bit to make sure it wasn't disintegrated or clogged, I replaced the O2 sensor. Once the old one was taken out, I was certain the O2 sensor was the problem.


It's either running rich, or the fuel overrun for the pops and bangs caused the O2 sensor to get covered in soot. I believe it's the latter, because the P0420 code usually pops up after I tap the gas at high RPMs for that pop n bang shenanigans. I don't think I've ever seen an O2 sensor running normally would get covered in this much soot. The other one was covered in just as much soot, but it wasn't throwing a P0430, so it should still be fine after I cleaned that one a bit. The code completely went away after I replaced it, even after removing the previous O2 spacers that I was hoping to alleviate the code. I'm hoping that with the VAP tune, that current A/F ratio would be more lean than stock tune. Fingers crossed I don't have to revisit this anytime soon.

 

I've replace 3 so far with another sitting on the bench waiting for my hoist to open up...

 

Could/Should these be placed on a preventive maintenance schedule, say remove and clean every 15k miles, or would it be better to just replace after they become fouled ?
Also what is the cost of the replacements?
Thanks
MM

 

That’s a normal amount of soot for the rear O2 sensor. If your running the VAP tune with pops and bangs it not uncommon for the cats to fail. It happened to myself as well as others on here. I’ve seen the cats fail on stock cars as well though.

 

With all the VAP tunes on this forum, I’ve heard of very few associated cat failures. I don’t think the failure rate is any more pronounced with a tune than without.

 

With all the VAP tunes on this forum, I’ve heard of very few (only yours and maybe another) associated cat failures. I don’t think the failure rate is any more pronounced with a tune than without.

 

I just had my O2 sensor replaced this week under warranty. My car only has 6000 miles on it. Guessing this may become a regular thing with these cars.

 

The above discussion raises the question:

Which came first, the chicken or the egg? I meant to say, bad injectors or bad catalyst?

 

Jags get a bad rap about failing cats from their past vehicles being a common thing. I'd like to think they're much better now. Bad injectors would also cause misfires.

No. O2 sensors are not part of any regular maintenance schedules, nor should they be. You're to replace them if they're broken. There's actually a few part #s that will fit certain sections of the exhaust system, that I found were actually interchangeable. T2H31272 in particular was the cheapest I can find that will fit O2 sensors post-cat. There is another PN, C2D54165, that works, but the part catalog says it works for 2013+ vehicles, whereas the T2H31272 sensor says it fits only 2016 F-Types onwards. Not sure what changed, but that's the only thing you need to be cautious of, that I know. Visually they look literally the same, one just has a slightly shorter wire, but made no difference.

Disagree. A "normally operating" exhaust system should not have this much soot, especially in a car with barely 13k miles. If you're talking about older cars that typically don't burn as cleanly, that is true, but I'd say cars from the past two decades at least have been able to burn fuel relatively cleanly. I put quotes around it because, even at stock, the system is outrageous on its own, being able to dump fuel for crazy overruns on demand. I can pull my O2 sensor from my daily, which has 18k miles, and it would look much cleaner than this. But it's relative. Perhaps it's "normal" for the F-Type, but certain not "normal" in a general sense.

 

Fair enough. It is certainly a subjective indicator at best. I was comparing it to the rear O2 I just looked at from mine last month while diagnosing the same error code. After watching the real time rear O2 data it was clear that both catalytic converters were dead at 38K when I checked. The dealer had no problem replacing them under warranty. O2 sensors were fine. This go around I plan on installing high flow 200 cell cats in a hope to avoid the same issue. Worst case I can put the stock ones back in when I go to sell it.

This is a new experience for me as I my only other British setup was a much more mild previous generation non-super charged 4.4L V8 with over 110K and no such issues. All of my other performance vehicles were German and Japanese and I've never experienced a catalytic failure previously running much more aggressive setups with larger turbos, forged internals, meth injection etc...

 

Lucky for you...my warranty expired lol...but yes, relatively speaking, I've never had to worry about cats failing prematurely, certainly not at such early intervals, and most certainly not while stock. Aftermarket, while you'll probably struggle to find an exact replica, spec for spec, as most of them will be high flow cats, may be more reliable. Honestly not sure why the cats fail, even on older models. You'd think making a cat converter should be open knowledge by now.

 

I spoke too soon. Guess I jinxed it

The P0420 code came back. Now that I know it's definitely not the sensor, here's the voltage reading on Bank 1 Sensor 2:




Bank 2 Sensor 2 has similar readings, but it's a bit smoother. Knowing the sensors are correct, that would mean the cats really could be bad...

The long term fuel trims are around +5-7% consistently for both bank 1 and 2. A bit higher than I'd like, but not unreasonable, and it's consistent. I don't think it's a vacuum leak.

So that really leaves me with just bad cats...hm. Guess my faith in the cats were misplaced, just like my priorities in life...lol.

Here's the thing though - OEM cats, new, are about $1000 EACH SIDE. VAP's sport cat is $1000 a PAIR. On top of that, it's less restrictive, and it may be more durable than the OEM cat. (REALLY not sure why the OEM cats would die so soon) The only thing I don't like about the aftermarket cats is it alters the exhaust note. IMO it sounds more raspy, not to my liking. Either way, I'm looking at new cats, it seems.

 

On F Types, a failure of Sensor 3 is much more likely than one or two. I've replaced many of those.

 

Would Sensor 3 trip a P0420 or P0430 though? I didn't think it would?

Either way I know the reading at Sensor 2 is fluctuating and it's accurate, so not much left for me to diagnose and just accept reality lol

 

Isn't there a longer, mandated warranty on emissions equipment like converters?

 

I'm gonna ask tomorrow to be sure...but generally I really dislike the Rusnak Jaguar dealership I have here. Always trying to upsell, no real knowledge in the service dept, always trying to weasel their way out of major warranty repairs. I'm still mad they tried to upsell me a set of new tires when my tires still have at least 15000 miles on them. The second nearest one is really far though...ugh.

 

In CARB states (like CA), cats are covered for 8 years/80K miles under the federal emissions warranty if the car was originally sold in CA.