So it says low efficiency cat 2. I replaced rear oxygen air fuel ratio sensor. No change I’m trying to under the meter readings , has anyone else had to change there cat underneath not the ones off exhaust manifold , or did you change all 3.

Anyone replace both cats off exhaust manifold? Is there a cat on rear exhaust manufold?

Anyone just change this cat The cat here is built into pipe so no cat on rear exhaust manifold?

Here it shows a 3rd cat anyone change this out along with any other cats ?

 

Hello,

The question I'm having is if you have a three-way catalyst? As far as I know, this system was only installed on a California spec cars, you can check it by the emission sticker on your hood.



This error may signify that your whole three-way catalyst system is at fault, since two other sensors go before cats and cannot check their condition. You need to do the testings first, that will dictate if you need to replace other catalysts.

Also, just in case, you can check your spark plugs, air and fuel filters, maybe even replace the intake plenum gasket, which is cheap and relatively easy to do (Part Number is 17176-62030).

Hope this helps and best of luck!

 

thanks. I never thought about the plenum gasket