Exaust Question

[doobsstang]

I just ordered an O/R H-Pipe and I am having a mechanic fix a Flowmaster muffler on my car. I told him that I was putting an h-pipe on and he told me that my MPG is going to go to hell. He said it needed cats so that the O2 sensors read correctly. He said the h-pipe will make my car run like crap and have CEL all the time. Is there any truth to what he was telling me or is it a bunch of sh**? I cannot go back now since I already ordered the O/R H-pipe and I dont want my car to run crappy. I dont see any reason not to put it on but he just scared me when he said my car will run like crap when I put it on...AAHHHH

 

[Mustangless]

I thought that I heard the cel will comeon but mine did not. It will not run like crap either. I do not have an o/r h-pipe but mine is gutted.

 

[loudpedal99]

Deleting cats will only cause a CEL on cars with front AND rear o2 sensors (which I believe are only OBDII like the 4.6 stangs). The front o2s are used for fuel delivery while the rear o2s are only used to make sure the cats are working. My car has been w/o cats for almost 50k; you'll have no problems with you car running like crap.

 

[SeventyMach1]

No, if anything, it will run better.

 

[ej95cobra]

Don't worry, the mechanic has it wrong. My BBK off road H pipe has bungs for the O2 sensor in it. Also, after market H-pipe with cats has the cats after the O2 sensors.

 

[doobsstang]

No, if anything, it will run better.

Heh...this is what I thought. The cats are clogged anyway...I would think opening up the airflow would be a good thing. The mechanic might just want me to spend the $700 he quoted me what he says is doing it the right way. My car only has 2 O2 Sensors...Is this like all other 94-95s? 4 cats and 2 O2 Sensors?

 

[TSWG00]

LOL the only time my CI cam on was when I was jut running open headers and Holy crap was that loud. Other than that with my H-pipe I have not had a problem. as for your MPG I didn't notice a difference. I did get ride of my knicking and pinging I had when I had the 4 cat H-pipe on lol. I know around here where I live the mechanics won't install O/R H-pipes because its illegal to mess with or take off the cats on cars or some crap liket that LOL.

 

[SeventyMach1]

Yes. Four cats & two o2 sensors on 94-95's. He is also probably one of those mechanics that WILL NOT install an O/R pipe because of "legal" reasons. If so, he will tell you you need a catted pipe. I've ran into a couple of those guys.

 

[TSWG00]

Yes. Four cats & two o2 sensors on 94-95's. He is also probably one of those mechanics that WILL NOT install an O/R pipe because of "legal" reasons. If so, he will tell you you need a catted pipe. I've ran into a couple of those guys.

what exactly is a catted pipe? LOL the person I took car to would not install the H-pipe so I had to drive my stang home with just my L/T headers it was fun and loud lol

 

[SeventyMach1]

what exactly is a catted pipe? LOL the person I took car to would not install the H-pipe so I had to drive my stang home with just my L/T headers it was fun and loud lol

A catted pipe is an intermediate pipe ..... with catalytic converters. The typical aftermarket mid-pipes have "high flow" cats. And they only use two, versus the factory four cat setup.

 

[95COBRA241]

There are 2 pre-cats and 2 cats. The O2 sensors are in between on a stock H-pipe. On a aftermarket catted h-pipe there a 2 cats and the O2 sensors come before the cats. So how would that affect the O2's when they read the exhaust b4 it gets catted?. If the O2's are working o.k. there should be no CEL.