[tomithy]

A few questions about aftermarket cats and emissions:

- If an aftermarket cat is installed on an obd2 car, will there be problems passing emissions?
- What about if you replace it with the stock cat for the test?
- Will I have to drive it around w/the stock cat back on for the ecu to readjust before the test?

 

[virus916]

i dont know about IL but here in CA aftermarket cat on obd2 vehicles are not legal. Must be an oem replacement. Just slap on your stock cat.

 

[crapmobile]

i guess it would be entirely subjective upon where and what kind of test it was. is it a sniffer, code check, visual inspection? besides i think we may have brought this up before somewhere

 

[tomithy]

i dont know about IL but here in CA aftermarket cat on obd2 vehicles are not legal. Must be an oem replacement. Just slap on your stock cat.

Actually I'm from VA... in IL for school and stuff. I figure I'll just slap on the stock cat... but will it be fine at that point? Or do i need to drive around for the ECU to readjust?

 

[fastblackgsr]

reset the ecu and give it 2 drive cycles...ie let engine warm up and cool totally..thats one cycle

 

[TheGSRGuy]

EPA laws are written that removing or modifying a functioning OBD2 cat converter is illegal. If there's a visual inspection, they'll fail you instantly.

 

[midwesta]

are you passing in IL or in VA?

If you are in IL then theres no real visual inspection. As long as you have no CEL with an obd2 car you should pass, so if u put the aftermarket high flow cat on, and you end up with a CEL then your screwed.

No CEL = pass

CEL = fail

 

[tomithy]

I have to pass in VA, where there is a visual inspection.

I guess what I really want to know is, if I switch the stock cat back on, will there be a chance I still won't pass emissions?and how do I prevent that from happening?

fastblackgsr said i just need to run the car 2 drive cycles for the ecu... will that for sure work?