lna

Hi Everyone, my GL550 hot check engine light on last month. Code read P0422, - Catalyst below efficiency. I erased the code and it came back a week later after 500kms. Then I ordered a botch downstream O2 sensor to replace passenger side. The same code came back again after one tank of gas. Now I'm thinking of cat converter. Dealer wants >$2500 to replace the passenger side cat.

Do I have other options? Please.

The truck is 150km now just passed emission warranty. MAF sensor was replaced a year ago. I really want to get rid of it before summer vacation. Thanks for any suggestions!

alx

if there are no additional bad o2 sensor codes, the cat is going bad and needs to be replaced.

lna

Thanks for reply.

Is there any after market cat converter for GL?

What are the consequences if I leave it as is?

alx

i am not aware of aftermarket cats for the gl550

you can run like that as long as you dont have emissions/ computer inspection in order to be legally on the road. a check engine light in my state is automatic inspection failure

lna

There is no emission law in my province. Just the CEL is really annoying to me.