Yours would be the first BHW catalyst that I have seen clogged. That said, there is no cat monitoring on a BHW. The only O2 sensor is upstream of the cat. You can remove it, but the car will stink. I have used a magnaflow universal cat for the Jeep liberty CRD as a replacement for one BHW cat that was rattling due to loose guts. Pipe size was a bit large but I swelled the ends of the downpipe to suit and tig welded it in.
Hi Quick TD.....Thank you for your reply - you are the ONLY one so far who knows if that upstream O2 Sensor will be monitored on a 2005 BHW's brain. As to this being the first BHW with a clogged Cat - I'm wondering too if the shop had the diagnosis right - more on that below.
I lost most of my power while going full throttle onto a highway - check engine light came on. The shop I took it too said it was either turbo related or clogged waste gate or a clogged cat....When the mechanic pulled out the O2 Sensor he is said the problem was solved when the back pressure was eliminated. So he said - clogged cat. We will order a new one from VW. I am not sure he actually test drove the car or would be familiar what full power was on my car.
So the shop was off to buy a new Cat from a VW dealer when they found out - VW has it listed as an obsolete part and no longer offered. So I'd appreciate your opinion on the next step as I have not been under my car - don't know what the cat looks like - only the shop has. You are giving me a much better understanding of a 2005 BHW Passat TDI Cat. So do I have what I write below - correct?
If there is only (1) single O2 Sensor that is -up stream of both the Oxidation & Reduction Chambers of the CAT .that single upstream sensor will never be able to monitor if there is either a Oxidation or Reduction Chamber down stream of it. There could be nothing downstream and that sensor will never care. As you said , remove it if I want, but car will stink.
That would be wonderful news not to have a Check Engine Light coming on. I'm assuming that Single Sensor would be the positioned in front of the first Chamber near the engine or what would be the "Oxidation Chamber and NO sensor further down on the the REDUCTION CHAMBER. Wonderful news.
There is a guy who makes a Straight Pipe (Techtonnic Tuning) to eliminate that First Chamber of the Cat or what I think is called the Oxidation Chamber - and he has a port for the O2 Sensor which I would have installed back in so the car does not stink. That gets me somewhere except for the Reduction Chamber that may also be clogged but no longer available....I assume just hollow it out would be your advice. Again, i have my suspicions too if this really is the first clogged Cat with only 66,000 miles on a 15 year old car.
So I'm wondering, like you , if it really is a clogged CAT ? Should I try the following to test the repair shop's diagnosis. First disconnect my battery for 10 seconds and reconnect the battery - to get rid of the Check Engine Light. Next with the O2 Sensor un-threaded from its port and the back pressure relieved as it streams out the hole for the removed O-2 Sensor - i should be able to drive the car for a few miles and experience full power again and no check engine light coming on ?
If that works then I should get what Techtonics Tuning offers which is a Turbo Down Pipe - it gets rid of the Oxidation Chamber and thread the un-monitored O2 sensor into that Techtonics down pipe. This alone might eliminate the back pressure - if not- hollow our the honeycomb inside the Reduction Chamber. I assume i'll hear more turbo spool up noise but i'm assume all is good if i do this - as i'm out of alternatives.
Lastly and a ray of hope if you run into this again at your end and don't want to do the Jeep Liberty CRD....Ebay is the only source in the world that shows it has a Cat for a 2005, 2.0 Liter Diesel Passat - it does Not say BHW.....it says " L4" and i don't know what ' L-4' mean unless it's the shape of the engine or ' in-Line - 4 cylinder?? It says Direct Fit. Amazing if true! Do you think that is , magically, the right Cat still made for a BHW or does the L-4 they post suggest something else llke a gas engine? Other than the missing BHW term it does say 2005 PASSAT 2.0 Liter Diesel. The 3 guys offering this newly made Cat that no one else today still makes ( not even VW) do show a diagram of the Cat if you are familiar with the shape. Do you think it's worth the $465 risk -yes I asked for a response from one of those guys on Ebay but no reply yet and no response from the State of CT for an Emissions Waiver - but I'm hoping that will come. If the Ebay item is real...i'd rather just do it right - even though Emission Stations can not monitor Emissions from a diesel - I hear rumored. The cost of Emissions Equipment for the low % of diesels is just cost prohibited - so they just look for Cells when testing a Diesel.
Hope to hear from you - Blair
Blair