Just purchased a simulator for my downstream oxygen sensor (after the cat). I did all the wiring and it cleared all CEL's I had that pertained to the oxygen sensor. My question here: because the CEL is clear, is this actually as effective as if I had a cat and an O2 sensor under the car? or did it just turn the light off? is there any concerns I should be worried about? shorting out my ECU; ect... Any info would be appreciated. The maker of this simulator is Magnum, bought it off ebay, has a 10 year warranty.

 

second O2 is extra. its just there to read the efficiency of the cat. no cat, no worries about if its doing its job...

 

Will I pass emissions with this simulator turning the CEL off?

 

you're probably not going to pass without a cat, then again i don't know how strict your emissions tests are.

 

i have had many cars pass without cats. as long as there is no visual inspection its very possible it can still pass.

 

What effects will a catalytic converter have on my car concerning performance and gas mileage if i decide to add one?