lynchy

Hi, I need to get two new Catalytic converters and wondered if I should stay with Lexus OEM or use something from a third party. Can anyone outline their experience and.pros/cons. Is there a particular third party product you would recommend?

Thx

samsonn25

I get the code sometimes, for cat inefficiency. But then again it could be the o2 sensor. 212k

lynchy

Real difficult to figure out. Both banks in my case so I wonder if it is something closer to the engine causing it? Don't want to get caught in the "let's swap parts" money hole.

samsonn25

Does resetting the code clear it and for how long? I am wondering since the engine is on and off all the time in city traffic that the cats dont get enough exhaust heat to have them at peak efficiency.

lynchy

Yes, I can reset the light and it goes away for a while but always comes back on. I am doing lengthy drives. Why thei ight does not come on immediately, According to the torque app it takes a while for the cars ECU to complete a re-analysis of the cats. To-date, I have changed the plugs, cleaned the airflow sensor and changed the air filter to no gain. These cats/headers are hugely expensive to replace in Australia from the dealer with what it seems is no other viable 3rd party alternative.

samsonn25

i HAVE BEEN GETTING THE CODE FOR CHECK HYBRID SYSTEM AND THE code shows cat inefficiency I also am slightly baffled. This happens 30% of the time and the other 70% of the time is traction battery deterioration. 215k miles on my car now.

This is what my portable scanner says, I also have Techstream but didnt check it out yet.

My light comes on every 80 miles or so.

lynchy

Do the codes show one bank or the two? For me I believe I need to rule out vacuum leaks next, (😁should be fun throwing propane at the intake manifold) but having said that I have ordered all new O2 sensors and although I do not believe they are the problem, I want new ones coz my car has done over 400k. If the cats were not so damn expensive, I would just do them first.

samsonn25

I have not checked it on Techstream because I dont want to carry around my laptop everyday waiting for the code to pop up.

Also I dont know why cat inefficiency would trigger the check hybrid system light?

lynchy

The check engine light only in my case. Cannot remember the two codes but in my case they mean bank 1 and bank 2 are no longer within their threshold.

samsonn25

I have slight exhaust leakI think this might cause my cat CEL. If the sensors read the car is rich it leans it out too much getting the cat TOO hot. Too cold is not good either, especially for the 450h which starts and stops alot in city traffic.

Burning too much oil clogs the cat also.

lynchy

Last weekend I replace "bank 1" exhaust manifold which includes the cat. I was a second hand unit from a low KMs example from a wrecker parts yard. Also added a new upstream O2 sensor. This solved the problem for bank 1. I intend to do the same to "bank 2". I also sliced open the old cat. Did not seem blocked but I am no expert. I will keep a close eye on Oil usage.can you tell me how much your car uses? I have new full synth 5w-30 in it. 1st change, only had the car for two months. BTW: Loving every bit of it.

samsonn25

Nice move with the replacement cat. I am replacing my front lower control arm next week im pretty sure the bushings are shot. Then diagnose where my exhaust leak is coming from.

My engine uses about 1-1.5 quarts every 5-6k miles. Currently 222k miles.

I have been getting cat inefficient codes and lean stuck O2 sensor signal Biased/Stuck Lean code P2195 Bank 1 sensor 1, as my exhaust leak has been getting louder, I think they are related. The theory is with an exhaust leak the o2 sensor reads rich and leans out the mix, but too much and the cats are over heated.

Also a new one P0031 HO2S Heater Control Circuit Low Bank 1 Sensor 1 which could mean a O2 sensor replacement.

lynchy

Now replaced bank 2 cat and added a new O2 sensor. No more codes. Yep in your case probably sort out the leak first, reset computer and then see how U go. For me it was a costly exercise. Glad I managed to pickup the low mileage cats, still cost $500 for the two sides and got the O2 sensors from Amazon 50% cheaper than the dealer. Next project for me may be water pump replacement as I am using / leaking some coolant and believe this could also be a good preventative measure as they are reportedly a weakness for these cars. Loving this car, hoping it hangs together (400,000+KMs on the ODO).

samsonn25

Well I got 2 new mid pipe sections welded in because there were like 6-8 leaks there right at the heat shields.

O2 sensor code was still there, and that makes sense because the exhaust leaks were after 2nd downstream sensor anyway.

Downstream sensore are alot more accessable. But I had problems with upstream.

Went to my friends shop to change out bank 1 upstream sensor, and we were there for 2 hours and couldnt get it off. It was very hard just to get the connector off and back on again.

The space is really tight and it was hard to get torque on it to turn it. We even broke a u-joint on the ratchet. We used PB Blaster and even a torch to heat things up again, no luck Is the solution an offset swivel flare crowfoot or to drop the midpipe (which the bolts look rusted) take out the passenger exhaust manifold (the header and front cat assembly) and then replace the sensor??

BTW the driver side bank 2 uipstream looks even harder to do.

lynchy

This may sound like a copout but, I'd recommend taking this to an exhaust shop. These guys remove O2 sensors all the time and seem to be able to reach places I never can. It was easier in my case as I replaced my exhaust manifolds with 2 the from the wreaking yard and they already had the sensors removed. New ones screwed right in.