Installing O/R H-pipe without tune

blbrchnk

New Member
Oct 16, 2006
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Bridgeport, WV
Will it hurt anything? Or just throw the engine errors? The pipe is here, but the tuner won't be here til Thursday or Friday and I am afraid I won't have the free time to install it for a while after this weekend. I saw someone in the gas mileage thread say they did this and it sparked my interest.
 
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I believe that it'll just throw a CEL but it won't hurt anything. I'd call a tuner to confirm. I'd still get a tune for it asap though. I mean they about $50-60 so it's not like it's a lot of money.
 
if you already have a tuner, just turn the function off with the handheld, nothing spectacular.

If your tuner allows it, tuners can actually shut off and turn off different sections of the tuner. I've heard of a few tuners who don't let the end user adjust to much and that's one of the things I've heard not allowed to be adjusted. :notnice:
 
That is ture but I would get a tune when you can

Read all of my posts man. I ordered the tuner a week ago this past Thursday from Doug at Bamachips. It has yet to ship out yet, but it will.

Thanks for all the answers. So what is it that they do with the tuner? I assumed they would adjust the O2 sensors since you are probably able to push more exhaust out without the cats, but is it as simple as turning off the cat sensors?
 
Read all of my posts man. I ordered the tuner a week ago this past Thursday from Doug at Bamachips. It has yet to ship out yet, but it will.

Thanks for all the answers. So what is it that they do with the tuner? I assumed they would adjust the O2 sensors since you are probably able to push more exhaust out without the cats, but is it as simple as turning off the cat sensors?

No there is a extream amount of code in the tune. You have fuel curves timing o2 on or off and a Hell of a lot more.
 
No there is a extream amount of code in the tune. You have fuel curves timing o2 on or off and a Hell of a lot more.

Yeah, I know that. I just meant as far as the O/R pipes. because from speaking with Doug at bamachips, he said he turns off the stuff for the O/R pipe for everyone, regardless if they have one now or not. I was only speaking in regards to the midpipe stuff. I know that he plays with throttle response and intake and all that jazz. But from what I can gather, he just turns off the cat sensors.
 
I can tell you from personal experience, that Doug turns off only the rear 02 sensors, however he leaves the front 02 sensor on.

As long as the rear 02 sensors are shut off, you do NOT need a revised tune for an off-road mid-pipe. You only need a new tune, if your upgrading to Long Tube Headers !
 
The front 02 sensors are the computers input for a/f ratio. The rear 02 sensors are only there to tell the computer if the cats are working properly. The signal the computer sees from the front is a sin wave as the A/F ratio constantly switches from rich to lean. The rear 02 shows a relatively flat line, because the cats take most of the oxygen out of the exhaust (to make co2 and water from HC and CO). This way the computer knows the cats work. Without a cat (or with a bad cat) the rear sensor will mimick the signal of the front sensor, and the computer will know the cat is bad or missing.

The only effect that will be had from not having cats is that the CEL will be on for catalyst effieciency below threshold, IE: bad cat. there is no limp mode or anything caused by this condition, because of the fact that all it is is a catalyst monitor. So you will not hurt anything by running the offroad pipe without a tune. I have done it on numerous vehicles.

In a tune, they simply disable the rear 02 monitor, so that the computer basically doesn't care wether the cats are there or not, this is only to keep the MIL light off.