Range Rovers Forum banner
1 - 7 of 7 Posts

·
Registered
Joined
·
17 Posts
Discussion Starter · #1 ·
My 2006 Supercharged has been throwing this code for the past couple of months. It indicates bank 1 catalytic converter, am I right to assume that this is the passenger side?

Truck has 139k miles on it, has anyone tried welding in aftermarket units?
 

·
Premium Member
Joined
·
2,467 Posts
There have been a few threads on this lately, but I will mention once again, these faults are usually cased by outside issues causing cat efficiency to be low, such as incomplete combustion, or burning oil.

If not done recently, I would absolutely start with a full tune up, including ignition capacitor, plugs and a PCV at the minimum, before throwing cats at it.
 

·
Registered
Joined
·
1,626 Posts
Cats certainly aren't the cheapest parts to start with.

Dave,
My LTFT on both sides are higher when I have my K&N air filter in (even with no oil applied) than when I have the conventional air filter installed.
I have cleaned the MAF sensor too.

Could that be influenced by the ignition cap?
Or maybe just an old MAF sensor?

I have an '03.
 

·
Premium Member
Joined
·
2,467 Posts
The ignition cap is built into the engine harness on the BMWs, and I have never seen one fail, the issue with the Jags isn't that the capacitor itself fails, but it will get a higher then normal internal resistance, and cause a voltage drop to the coils' power feed(the unit is wired in series with the power, but the cap itself is in parallel)

As to the fuel trims, assuming the K&N is sealing correctly in the air box(is this a drop in, or cone style? - same thoughts apply for either), it shouldn't make a difference with fueling, as the engine dictates how much air passes through it(assuming the paper filter is not clogged) That said, due to design, and the K&N being able to flow a large volume of air, I could see some turbulence being created, slightly throwing off the MAFS reading.
 

·
Premium Member
2006-2009 Range Rover MkIII / L322
Joined
·
694 Posts
I can tell you from the software that the thresholds for Catalyst diagnosis in the 03-05 BMW equipped rovers is VERY high. The BMW x5 for instance (same engine, very similar calibration) has nearly 50 percent more stringent requirements in order for the catalyst to pass diagnosis. The euro software is similarly stringent, just the US models appear to be lax.

As for the K&N causing issues, there are maps in the ecu which dictate fueling corrections based on the design of the stock air intake system. Any change to the intake tract will cause trims to change a bit.
 

·
Registered
Joined
·
1,626 Posts
?..
As to the fuel trims, assuming the K&N is sealing correctly in the air box(is this a drop in, or cone style? - same thoughts apply for either), it shouldn't make a difference with fueling, as the engine dictates how much air passes through it(assuming the paper filter is not clogged) That said, due to design, and the K&N being able to flow a large volume of air, I could see some turbulence being created, slightly throwing off the MAFS reading.
It is a drop-in, same as the OEM.
LTFT for bank 1 runs around 18, bank 2 around 14 at highway speeds, and drops to about 16 and 14 respectively at speeds below ~50.
With a disposable filter in, it stays about 5 or so points lower.
I can switch between the filters and watch the LTFT change accordingly, repeatably and predictably.

Thanks for your helpful feedback.
 
1 - 7 of 7 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top