removing the cat

[turboSR5]

I'm going to go with 2 1/4" from header to tip.

 

[Chichi]

Exhaust fumes smell like ammonia.

Has anyone experienced ammonia smell from exhaust fumes coming in through the back window?
I've had poor gas millage for some time now, I'm thinking it's CAT converter. Before I go ahead and pay the $250, I wanted to check in the forum to see If anyone has improved fuel millage by replacing CATs...

 

[Bad_Vision]

yup i get it all the time. it aslo can be gear oil smell they are close in the smell meter.