I just ordered a test pipe for my 03 Civic EX. Someone told me that the test pipe will definately make my check engine light go on causing less power. What is the situation with this, will the O2 sensor absolutely make the check engine light come on with the test pipe? The shop I bought it from said I shouldn't have any problems.....

 

1 - check engine light on ... yes
2 - lose power ... no
3 - make your car smell awful ... yes
4 - legal for the street ... no

unless you're pushing some serious boost or making a ton of n/a power, you shouldn't even be considering a test pipe.

 

I talked to a guy today at Sin City performance here in Vegas that said when the "check engine" light in the car goes on, it goes into a "safe mode" which makes it lose power....

 

Oh, and I'm registered in Utah, so no smog or emissions to worry about, just safety inspection and they dont even look at the underbody of the car...and I can live with bad smell....it just fits in with Vegas But I hear I'll see at least a little bit more power

 

It depends on what you have done.
If you have the basic bolt-ons then you just wasted your money on the test pipe...what mods do you have to justify the test pipe.

 

I have AEM V2, Megan Header, and Tsudo Exhaust.....and the only other thing I've done is add the Denso Iridium plugs just for fun....so if I wasted my money on the test pipe should I have gone with a high flow cat instead?

 

Yeah,
Test pip;es are really only benifitial at the track when you want to run open exhaust. Your not going to gain any power by adding that. Your money would have been better spent on the high flow cat...

 

so how would i gain more power with a high flow cat? isn't a high flow cat even more restrictive than a test pipe would be? i really don't care about low end power....i always have the bad boy rapped out anyways

 

It will create so little backpressure that you will probably lose power since you only have mild bolt-ons that require the lower backpressure. You can kiss the little amount of torque your Honda engine has, good-bye. A high flow cat flows better than the stock cat but still maintains some amount of backpressure to ensure most of your torque isn't lost.

Since the check engine light will go on, the engine will go into limp mode and you will lose power. Since the O2 sensor isn't there any more, your engine will have to guess how lean/rich you are running. I would just say stay away from the test pipe unless you have a turbo setup or high-flowing N/A setup that requires it. And you would be doing us all a disfavor by stinking and polluting the air.

 

Okay, I ordered a test pipe to replace my cat and the consensus seems to be that I wasted my money and should have just gone with a hi-flow cat because the test pipe will make me lose power, or at least torque. So here's my stupid question of the day. How come not having a cat doesn't affect older cars or non-import cars? Exhaust uses the same principles if i'm not mistaken no matter what vehicle it's on....so I guess I just don't understand how getting a less restricted flow through the exhaust could be a bad thing. Catalytic converters haven't been around forever and to my understanding are only an emissions device and that's it. I know my first car, a 61 Chev p/u didn't have a cat, it just had the pipes right back to the glass packs.

Again, i'm not arguing any facts what so ever, just trying to get a straight story...Thanks