I'm not really sure If there are multiple issues here?

I've been chasing a constant issue with a P0171 code since I've been here. I also have the occasional P0400 and a P0420.

From what I understand..both these faults make me look at bank one. The fuel trims one bank one look like this....



You would think I have a vacuum leak as large as your thumb on bank 1?

Holiday decorations done today so I took the time in the shop to pull the convertors off both sides. Bank one looks fine.. although it set the code..

Bank two convertor looks like this..





I didn't bring the appropriate tools with me to the shop today to just gut the catalytic converter for bank 2.

Basically..I'm asking if a plugged Cat on bank 2 can cause lean codes on bank one? Or am I chasing 2 different issues?

Thanks in advance.

 

Come on JagV8...

Help me out here please.

 

Can't really help whether a cat problem can induce lean fault codes.

But I don't think you can hollow out a converter on a 2003+ model without causing more trouble. 2003 is when Jaguar switched from narrow band O2 sensors to wide band. Through 2002, the downstream sensors only monitored catalyst efficiency. But with the switch to wide band, the downstream sensors have the additional function of fine tuning fuel trims.

With a hollow cat, this expected input will be way out of range. I'm not sure how the computer will respond with only partial feedback for fuel scheduling. It might even stay in open loop mode, and cut way into performance and fuel economy. Worst case, the computer may go one step further and convince your daughter to marry a drummer. Not sure you'd want that to happen.

 

I'm not keen on that graph as I can't really grasp it, but I'd for sure want to know what both banks are like. If you start with the usual hot engine, parked, at idle & about 2500rpm and it's mainly the LTFTs so long as the STFTs don't look like it's desperately trying to learn (i.e. not in the process of moving the LTFTs significantly).

Sorry about the delay but been, er, en famille

If you can read the freeze frame data it would be worth doing, too.

Yes, by 2003 you'll have widebands. You can fool the PCM using (rear) O2 extenders I gather, but it's illegal here anyway so not something I'd go near.

But first let's see what data you can gather if you're willing/able.

 

I agree. It looks like the ltfts are high positive but stfts are high negative???

am I seeing thst wrong?

 

If your state has periodic emissions testing for registration renewals, you are eventually going to have to deal with a proper replacement anyway... There are perfectly adequate catalysts out there in the aftermarket that will not break the bank like an OE cat from Jaguar would.

 

Thanks to all who have responded.

I’ll get both banks loaded for review.

I absolutely plan on replacing both converters very soon. Rock auto has them at a decent price.

Thanks again.

 

All-

Reconnected the scanner this evening..I figured since the graph was a tough read I set things up to just read values..

Idle at full temp..


Idle


Then at 2500 RPM.


2500 RPM


I hope this helps!

Thanks

 

They look rather worrying.

I think I'd check both cats next as one or both may be blocked.