Hi I have a 2010 Jaguar xfr my check engine light comes on but not all the time when I had it diagnosed they said it's bad catalytic converters they're not even a year old because the dealership had changed them does anyone know if there's anything I can do to clean them out or maybe some method I could use to keep that check engine light off because the car runs great even with the light on intermittently I thought maybe I can save myself $1,000 if there's another way to solve this issue any input would be great thank you

 

If its code p0420 or p0430 it might just be a small vacuum leak. I replaced my catalytic converters because somebody had welded in a pair before I got the vehicle but they did a terrible job welding them in and the connecting pipes that they used were much smaller than the existing pipe sizes so I didn’t like that because obviously obviously Cut down the exhaust flow.

when I took the exhaust pipes off the car I looked at the catalytic converter grid material thru the pipe and thru the 02 sensor holes end it looked like it was in good shape so I kept the pipes I took off in case I need some parts later. But I didn’t replace them because they were bad. I replaced them because of the horrible weld job that was done.

I used aftermarket Exhaust pipes that have the cats already installed in them but soon after I was noticing I was getting a catalytic converter efficiency code P0420. Only on bank 1. Bank 2 was fine

Previously I had been chasing a bunch of vacuum leaks that was causing me to get a bunch of the lean bank one and lean bank two codes for many months prior to this. Every time I would find a leak I would claim success Only to find out the code would come back within a month or so. I would do another smoke test or change more O-rings or intake gaskets etc and this went on for several months.

I finally got the P0171 & P0172 lean codes fixed! Or at least they stopped coming but now I started getting periodic cat efficiency codes but only on bank one. I took that exhaust pipe and cat assembly off the car and looked inside the pipe at the converter material and it looks fine. But I noticed the flange on the exhaust pipe where it connects to the exhaust manifold had a small raised bump where the pipe seam was welded when the pipe was originally manufactured. The flared the end of the pipe might have leaked where it connects to the exhaust manifold bc I was getting a small bit of exhaust soot there . It was tiny. So I took a file and smoothed down the bump at the mating flange surface and I reinstalled the pipe. I got the same cat efficiency code on bank one a month or two later

Using the monitoring functions on SDD I was able to look at the short term fuel trims and the current output for the bank 1 & 2 O2 sensor 1 and The voltage output of O2 sensor two on both banks while I sprayed tiny amounts of carburetor cleaner in various locations around the engine O-rings gaskets intake exhaust etc. and I noticed I could get the signals to wiggle when I sprayed near the back of the engine by The fuel injector at the rear of the engine but I couldn’t exactly tell where it was coming from. Could’ve been the EGR or one of the vacuum lines over there or the intake manifold gaskets or injector O-rings. I moved around some cables back there and saw thd signals wiggle so thought maybe the fuel injector was the cause. I wiggled the fuel injector back-and-forth to try to see if i could seat the O-ring and voila the code went away.

The lesson to be learned is that the cat efficiency code can be caused by a very small vacuum leak and it’s not necessarily a bad catalytic converter