Replacement Cat for 2003 3.4L

So the catalytic converter is in need of replacement I think. It is the only thing on the exhaust that has rust and hasn't been replaced. The reason I think its going is because I got codeP0037 (Circut Low Bank 1: Sensor 2), but I don't think the sensor is really the issue. I think the cat is. I just replaced the exhaust and some other parts before the cat were replaced when I bought the truck. The cat is still original.

Anyways, I got a new denso sensor at the store to repair it, but if that doesn't do the trick and it really is the cat, does anyone have a recommendation? The OEM is 1k+!!!!! and thats too much IMO.

Thanks in advance.

 

I can see that being true if you're in CA; other states don't even have smog testing so a universal CAT will suffice.

 

So will any old' one work? I'm guessing it will take some welding on by a shop since I can't weld. I am in MA and as far as I know we don't have smog testing yet.

Thanks.

 

You can get andequate aftermarket bolt in cats as well. 399 for the one I need at my local auto parts store


I would go there and get them to use their fancy scanner to track live data and map out the voltage readings for the front and rear O2 sensors

If it looks like this toy need a new cat.. cheaper to test first before buying and replacing expensive parts

 

Plenty come up on the used market.

Is your CAT rusted through?

A CAT going bad usually has the rotting egg smell as an indication.

 

I will check the smell but haven't noticed a ton, maybe I can just change the sensor and that will do the trick.

As far as the auto store checking it, they had me plug the reader in because they aren't allowed in peoples cars right now? Not sure if I can get my hands on that sensor scanner.

 

save yourself some money and buy an Underdog racing rear o2 sensor simulator apx $100. It plugs into the O2 harness under the passenger seat so it is hidden. It WILL flatten the curve of your rear O2 sensor. In Abeyancers post it is clear that the rear O2 sensor mimics the front O2 sensors wave form. The URD simulator knocks the peaks off of the signal and smooths the wave.

 

A guy at work just ordered and put in a 90 degree oxygen 02 Sensor socket from Amazon. It fits between the catalytic converter and the O2 Sensor and has a mini catalytic converter built in. His was for a F150 but I'm sure they make them for Toyotas as well. This was the one he ordered. Maybe different for a Toyota: https://www.amazon.com/dp/B07VMJQJSR/ref=cm_sw_r_sms_api_i_oeIeFbP33RDGY

 

https://www.amazon.com/dp/B07QNJJQC...wVehicle=1&vehicleId=2&vehicleType=automotive

 

I have the replacement sensor, and am going to put it in tomorrow. If that doesn't clear the code and fix it, I'll have to consider this vs just replacing the cat. Its literally the only piece of the exhaust besides the headers thats still original.

I'm hoping this sensor will fix the issue though.

 

Not having to meet CARB standards I use Walker Products

They fit bolt on and are not Super expensive

 

I saw some of those when looking, seemed reasonably priced.

 

New denso 02 sensor seems to have done it. Light cleared and I drove for 30 minutes and it didn't come back on.

Thanks for all the advice and help!