Engine Warning Light After Cat Change

[Geordieboy5]

Good morrow fellow Toyota Fans. I have recently come across an issue with my 123k mile Avensis. It is a 2000 model 1.8vvti manual (That drinks oil). It recently failed its MOT on emissions......CAT was blowing. I replaced it and the clutch and it flew through the MOT......then the engine warning light came on. The garage said that the left bank of the CAT was out. I took it back to the Garage as the CAT has a 2 year warranty, and they fiddled with it....reset the ECU......and the Light came on again. Another thing has happened since I changed the CAT. I used to get 42mpg on AVG all the time.....now I am down to 36.9mpg. That is a significant drop. It has had the prerequisite oil/plugs/filters.....but it all changed when the CAT was replaced. Now as I am a tight @rse, I just got this all done at my local garage (whom I trust). Can any of you guys help?????

Cheers

[bestseany]

Maybe one of the lambda sensors is damaged from the oil that's being burnt by the engine?

[Geordieboy5]

That is a very distinct possibility. She goes through a litre every 1000miles easy. Is there anyway to check? The diagnostics (not Toyota) only show the left bank of the cat out of threshold. ????? I use 5w30, but am thinking of going to 10 w 40 oil to stop the burn so much. What do you think?

[Gooli]

Well, if the car has done 123k miles, the oxygen sensors could be on their way,

even if the engine didn't burn any oil.