Just wondering if anyone else has installed test pipes and if so have you noticed the fuel mixture running richer. I have noticed that car has an extremely strong rich exhaust smell and the exhaust tips running much more of a black color as opposed to the grey it was running with stock cats.
Like I said I am running helix test pipes with Nismo exhaust.

 

You aren't running rich, you are incompletely burning your emmissions and they are accumulating on your tips. It could be a little unburnt fuel as well. But you are not rich. If anything, you are a little leaner. The Z gets black stuff on the tips even when stock.

 

Thanks

 

I installed the helix pipes two weeks ago and my gas milage is decreasing by the tank...but I don't have the black build up on the tips anymore.

 

Yea, I have been noticing that myself and I have had mine on for a week, but at the same time I have been putting my foot in it a lot more often.

 

Whats interesting is that the first day or two after getting my high-flow cats, I didn't notice much gain, smelled harsh, and my gas milage was down to 18-19. After some miles on the odo, this all changed. Gas milage is back to 20-21, smell is mostly gone, and theres noticable gain. I'm pretty certain the ECU takes some time to adjust the map..

 

putting your foot down might be the cause for the lower gas milage. But, I just finished another tank of gas today and it was about 25 miles off of what I usually get on a tank. And I didn't go over 3grand the whole tank... oh well

 

How do the Helix test pipes sound? I want to get a set, but I'm worried that they will sound raspy. Any opinions?

Scott
'04 M/T Performance

 

All test pipes sound raspy. They are all just straight through pipes. It isn't really scientific.

 

IMO, with the NISMO exhaust they sound like a bunch of angry hornets in a 50 gallon drum. I love the sound and everyone that has heard it says it sounds awesome, I am 38 and I do not like that Honda raspy sound and this is no where near that sound.

 

I am trying to decide on either test pipes or High Flow cats. I want to know what the bennefit is for one over the other? Obviously most Hight flow cats will pass a smog check which is a big plus, but from a performance standpoint, what is the big bennefit for using test pipes over high flow cats?

Also, will test pipes give you a CEL? If so, is there a way around it?

-Chrismcagle

 

I like mt RT cats

 

i was running very rich with my RT cats...

it all depends on how you drive the car...

doesnt matter as much if you are running lean down low.. obviously not too lean though...

 

Jason you just have a weird car. Everything it does is opposite of every other car in the world. It's def. not normal.

 

Well test pipes replace the cats. And without the cats filtering the exhaust, you're going to have more pollutants and stuff coming out of your tail pipes. So that's probably what your smelling. It also probably whats contributing to that black color. I had a 95 Talon Tsi AWD with test pipes, and that shiet did not smell good.

 

I know a bunch of cars that run rich on RT Cats...


but then again... all those cars are always above 4500 RPM for the most part...

where the car runs RIch no matter what you have pretty much.... lean from 4000 and below yes...


you dont want to know how rich i have been running...

running rich is very bad... very very bad too... you need to find the rite mixture... ill work that out after i get my car back from the shop...

 

The car feels like it did not pick up much on the bottom end, but 3000 and up it definitely feels stronger. Have not dynoed yet with Test Pipes but will have to do so soon. I appreciate everyones input.

 

Could the increased flow of gases be incorrectly influencing the A/F meter to show a rich condition?