efficiency of high flow cats with a cam?
 

i have a question about high flow cats, with our cammed camaros.

when i went to pick up my car from the shop after a cam job, i honestly cannot remember exactly what he said. but i know it was something about cams not being emission friendly or something of that nature.

so my question, even with high flow cats plus correct tune our cars still are not emission friendly and would fail a smog test ?

Thats an interesting question. Fortunately my area don't check emmissions ;)

ya same with my area, which is why i am not really worried about it. but still something that i rarely seen talked about.

You may be asking a simple question to a complicated answer. However, generally speaking a car should pass the smog test as long as there is not a CEL, and the tuner has not turned it off for this particular code. Every car and engine combination has its own CO and CO2 emissions specifications. The CEL should trigger if those specs are exceeded by certain limits. However, I am not sure that all state smog tests allow for the same spec variance that every car's CEL trigger sensors do.

I can say that I have modded plenty of cars in Texas, and always passed the smog test as long as I did not have a CEL.

2 or 3 people at the shop told me mine will pass with the cam and high flows and the guy who actually did the work told me if it doesn't he'll fix. On the other hand, I'm going to have to hope the people doing the test have a head cold that day because it doesn't smell like it will pass. We get 4 or 5 years before we have to go, and who knows what the rules will be then. We're not supposed to talk politics here, so I'll just say if the wrong people get elected the whole country could have rules like California in 4 more years.

hahah right.

In CA, we have the visual, OBD hook up, and sniffer test done when we smog our cars. Yes they check everything. I heard starting in 2013, they are going to stop with the sniffer test and only do the visual and OBD hook up. So I would think that if your tune is good and you're not throwing any codes, then you just have to worry about the visual. Every single shop that I have brought my previous car to are complete dolts. They couldn't tell you the difference between an intake manifold and a door knob. So as long as your readiness codes come back perfect, then you're good. By the way, it has yet to be determined if tunes will some how make you not pass. I heard that they have some sort of stock parameters that they get from the state/manufacturers and if it doesn't match your ECM, then you fail.

ya thats what i was talking about the sniffer test. i thought the nature of cams with the valves being open longer its bond to let more gas escape. i watched a movie on cats, they said once cats were warmed up they stop 99% of Co2 gas. i was wonder if high flow cats with a cam would also be 99%.

I thought you were cammed?

He is and is just wondering how effective his HF cats are at burning off the exhaust vapors. I'm curious too since I have a cam and HF cats as well. I know one thing the cats are doing something because until they heat up I get a lot of tail pipe vapor/odor on a cold start. Once runnning for a few minutes the odor goes away. Odor aside - not sure if they are burning off 99% of the CO2 though.

I'm actually glad to hear that because if I let my car warm up in the garage it gets a bit smelly in there. Smells just like when I used to have a garage that was 10 feet lower than the street and had to warm motorcycles up in the garage before riding up hill to the street. I thought maybe it was something with my tune making it run too rich on cold start but it sounds like that is normal.