would you gain or lose performance? this has prolly already been discussed on here and if so sorry for bringin it up again. anybody felt any gains like 12 hp?
AJ'S 88NA said:Yeah I did the samething, and I believe it will make you run a little richer...
I thought without the Cat it would run a little richer???CRE said:How would running a test pipe cause the ECU to start adding any significant amount of more fuel to the mix?
I guess you gave the best explanation. Maybe if you had a cat that was fairly pluged up, is why people feel that it makes a difference?CRE said:Not as far as I know. Here I was expecting a good explanation as to why people keep saying that too.
It may *smell* richer since the cat isn't helping to break down excess hydrocarbons, but I can't think of any reason why it would actually cause the mixture to change.
AJ'S 88NA said:At that time I thought it was running richer due to the smell. Didn't have a AFR gauge to check.
CRE said:Well, even a good high flow cat will create some restriction... I'm not debating that a test pipe may or may not free up some power, just pointing out that it's unlikely that it'll change your fuel mixture (I've seen that posted a lot lately).
On a Cali. spec car it could effect the fuel mixture as there is another O2 sensor between the two cats, but the rest of them I don't see it happening.