Has anyone tried smogging their s5 with racing beat headers and an aftermarket cat? Did you pass? Was it close or easy as pie? Whay kind of cat? Thanks

 

Not gonna pass. The headers will flunk visual.

You might be able to pass in arbitration, but you will not pass at a test only station.

 

With a decent cat you should pass the sniffer but as icemark stated, you'd fail the visual. Some places don't some places do, but technically you'd fail.

 

I'm not worrying about the visual but more on the sniff test.
So would a bonez high flow cat work? Any other suggestions?
Also do you guys think 1 cat is enough since the original system has like 3 cats and exhaust manifold

 

I pass smog with one large GM cat with the stock flanges welded on. I'd imagine that most any decent sized cat, in new or good condition, will be alright. The precats were mainly there to improve emissions when the engine was cold. So technically, the precats being removed should make you fail the visual (but not the sniffer), but I've never had a smog tech mention it.

 

when i lived in cali usually if you go jiffy lube they dont really do a visual and its the same in NC they dont do a visual of the underside they will just put the sniffer on it. make sure the car is nice and warm before you bring it in to be inspected.

cali also has a clause that if you fail they will give you an amount of time to have it fixed, if you try to fix it and it still fails they give you so many times before they automatically pass it and you dont need to get it smogged.

 

[QUOTE=Druken;8942264]I'm not worrying about the visual but more on the sniff test.
So would a bonez high flow cat work? Any other suggestions?
Also do you guys think 1 cat is enough since the original system has like 3 cats and exhaust manifold[/QUOTE


yup...one bonez high cat will work. I passed with fly color with bonez high flow car system and new o2 sensor....I am selling the bonez high flow cat if you wanted. it pratically new..

 

The two pre-cats are only used during the warm up process. Once the engine is up to temp, then the pre-cats are too hot to work, and no longer converting HC.