O2 Sensor H-Pipe Question

[bmxelvs]

Ok to make a long story short here it goes... I bought a used 2000 Mustang GT with lots of mods already done, but it wouldnt pass smog so the dealership took it to a muffler shop and had new cats put on. One of the old cats had been gutted or had come apart thus it wouldnt pass. So the muffler shop put on two new ones, only problem they put on the wrong size, and they installed them right where the long tube headers dump into the H-Pipe so the car dropped significant horsepower, didnt want to rev ect... When I jacked the car up the cats were already turning gold (Obviously getting to hot) after only 100 miles, so I took the car to a different muffler shop where I know the guy and paid him cash to cut out the cats and just weld in straight pipe, thus essentially creating an offroad H-Pipe. Now here is my concern after doing this, I have the O2 sensors threaded into the H-Pipe just like they were before only without cats and I am concerned that now the sensors are going to be reading the exhaust as rich and tell the computer to lean out the car. The check engine light has not come on yet like I thought it would. Will this hurt the car? If you go out and by an off road H-Pipe do they have holes to thread in the O2 sensors, or do you just remove them and put bolts in the holes? I have heard something about MIL eliminators, but until I get them can I safely drive the car as it is? Sorry for the long post and thank you all very much for taking the time to read this and thank you for any input.

One last note here is what is on the car: K&N in the fender well intake, Under Drive Pulleys, Pro 5.0 shifter, Ceramic Coated Long Tube Headers 2 1/2" H-Pipe without cats, Raven Mufflers with 3" tips, 4:10 gears with posi-traction.

[bmxelvs]

I thought of a couple more questions... What should I do next in regaurds to mods? I have been considering a plenum? If I do get a plenum any particular brand? Or a chip of some type just because the speedo is off like 10 percent... Or maybe there is something else that people are doing to the GT's to get good power gains... This is my third 4.6 mustang, however I have been out of the scene for a while. Previoulsy I had a 1996 Cobra and a 2001 Mustang Bullitt both of which were completely stock...

[gtjeremy]

mustangsunlimted.com look up MIL. problem solved. $74. shuts off engine light

[xxxBlakexxx]

Originally Posted by bmxelvs

I thought of a couple more questions... What should I do next in regaurds to mods? I have been considering a plenum? If I do get a plenum any particular brand? Or a chip of some type just because the speedo is off like 10 percent... Or maybe there is something else that people are doing to the GT's to get good power gains... This is my third 4.6 mustang, however I have been out of the scene for a while. Previoulsy I had a 1996 Cobra and a 2001 Mustang Bullitt both of which were completely stock...

If you get a tuner o0r a chip, it can be programmed to turn-off the SES for your mid pipe. If one is in your future anyway, just get it now, cuz the money you spend on a speed cal and mil eliminators would get you almost half-way to a chip.

I recomend SCT products such as a chip ($325) which can hold 4 custom tunes that you can switch on the fly, or the new XCalibrator which retails at $375 I believe.

Here is a nice little write-up about the differences between chips and programers at another site:

http://www.mustangtuningforums.com/showthread.php?t=19

PS - I am the author

Also, a plenum and throttle body is a great mod. They will net you proven gains, though not a lot, but will also improve throttle response. A good combo will get you around 12 rwhp. I recomend either an Acufab setup such as this:

http://www.mustangtuning.com/ac42v75thbop.html

or go with a C&L Plenum and a BBK TB.

- Blake

[bmxelvs]

Thank You very much for the input! A lot of really good information there, I think I will go with the XCalibrator as I have no need for different tunes at this time... The throttle body/plenum was already on my list, how hard of an install is it? Does it just bolt on or do I have to mess with the tps at all?

Also my check engine light still has NOT kicked on and I have put like 500+ miles on the car already with no cats which I think is pretty strange. Maybe it has something to do with the ceramic coated long tubes?

Lastly since I pulled my cats the mufflers I have on the car dont really sound that great. I have Raven's on the car right now. Anyone have any ideas on what would sound the loudest without sacrificing too much sound quality with my exhaust set up e.g. long tubes with 2 1/2" H-Pipe?

Once again thank you for the reply!

[xxxBlakexxx]

Originally Posted by bmxelvs

Thank You very much for the input! A lot of really good information there, I think I will go with the XCalibrator as I have no need for different tunes at this time... The throttle body/plenum was already on my list, how hard of an install is it? Fairly simple install. A few botls and hoses. That is about it. Does it just bolt on or do I have to mess with the tps at all?The TPS is the toughest part of the install. You have to swap the TPS from the old to the new plenum. The bolts are a bitch to remove...or can be. Sometimes the TPS will get damaged in the process. You might need an impact wrench top break them loose. Be prepared to buy a new TPS. They are not that expensive ($40).

Also my check engine light still has NOT kicked on and I have put like 500+ miles on the car already with no cats which I think is pretty strange. I have heard of that happening. Don't be surprised if the light does not come on eventually. Maybe it has something to do with the ceramic coated long tubes? Not sure about that. I don't see the link.

Lastly since I pulled my cats the mufflers I have on the car dont really sound that great. I have Raven's on the car right now. Anyone have any ideas on what would sound the loudest without sacrificing too much sound quality with my exhaust set up e.g. long tubes with 2 1/2" H-Pipe?IMO, catless mid pipes usually sound like crap. Makes the car sound rough. I know it is a personal thing. Sometimes, IMO you can get away with it with the right muffler. But I can guarentee you that there are not many people with Raven mufflers and a 2.5" catless H pipe. The trick to finding a good sounding exhaust is to have the right components working together. I am not a big fan of mixing and macthing brand names either for this very reason that you are describing. Companies design their components to work together. When you mix and match, you run the risk of a bad setup. Unless you have heard them before hand. For example, MAC Prochambers are commonly used with FlopwMaster American Thunder catbacks. While not appealing to everyone, it is generally a winning combination. In truth, I think a catless H pipe is the hardless thing to get to sound right. Why? Simply because it is not as commonly used. One more thing, with a catless mid pipe, the louder you go with the mufflers will no doubt sacrifice sound quality. Ask around and see if you can listen to a similar setup like yours but with different mufflers.

Once again thank you for the reply!

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