Stix66

So I am (have been for a while) planning on getting rid of my stock midpipe and wanting to go with a cat-less one.

I have an oppurtunity for a friend of mine to be able to straight pipe it from the headers to my flowmaster set up in the rear end. Is this a good idea, or should I buy a name brand pre-made midpipe for the stang. Does it make a difference?

svopaul

That all depends on what your friend is capable of.....I have yet to see a fabricated mid pipe that is as nice as a bolt in H or X pipe. Will he put it in with ball flanges or weld it straight to the mufflers? If he does not install ball flanges like factory then good luck when it comes to having to service the transmission, you'll have to cut off the exhaust and reweld it.

foxhtn

Also, what about sensors and backpressure? Would'nt that alter the computers memory and affect low torque output?

svopaul

You need the Oxygen sensors in there but it doesn't affect anything with the computers memory, only how it functions based on the readings of those sensors.

Back pressure is needed but mufflers will give enough back pressure, I don't think torque output is even going to be a factor here.

Stix66

The 2 oxygen sensors I have though are before any of the cats, so it will not even alter the readings I will get with the cats being off.

I am going to see what his plans are on doing with the route and the way he is going to connect it (pretty sure it is ball flanges) I can not see him going the cheap weld it on way.

Otherwise I was just going to get a new Mac H-Pipe off ebay for $120 + S&H, and then install it myself.

Stix66

Ok So I installed the off road midpipe, and It was all running fine and sounds really sweet! After driving for about 15-20 mins, the check engine light comes on. I am guessing this is because of the back pressure and all. What do you guys do to keep the light coming on and fix the readings to the computer? Because won't this hurt the exhaust valves and burn them up without enough back pressure? I still have the mufflers on and still have the air injection routed in place, but I guess they are not making enough pressure to keep the light from coming on once the engine gets to N.O.T.

Any suggestions?

Valentino

after I installed my off road H the check engine light came during the first drive but went off and stayed off. I eventually put a scanner to it and my only codes were for the EGR so I guess the computer worked things out.

Stix66

Yeah after I turned off the car, when the CEL was on, It hasnt came back on when I turned the car back on yet. But I wasnt driving for more than 10 mins.

Tomorrow I am gonna have to do some driving so if it comes back on I will repost.

Thanks Valentino!

svopaul

It has NOTHING to do with backpressure....Run a code scanner on it, most of the time you get that light it is an EGR fault code and often the electronic unit found on top of the EGR valve. CEL lights are emissions related.

Stix66

It came back on tonight too.

Probably a stupid question, but, if it comes up as an EGR fault code what do I do?

svopaul

Fix it.....check the EGR valve and make sure it is not clogged up and that the diaphram works with vacuum(just suck on the vacuum port and see it it opens. If all that looks good then it is likely the electronic unit on top...replace it.

Stix66

Yeah I knew it would have been a stupid question lol. I just don't know how the EGR valve suddenly pop the code once I put on an off-road pipe on and not before.

Thanks!

svopaul

It may just be coincidence....

Stix66

Well I read the codes and it turns out to be this:

HO2S (sensor)
(Bank 2)
Not Switching

So it is an O2 sensor... I am gonna get under the car and see if it got loose and plug it back in and all. If that does not work I will just buy a pair of new O2 sensors this week. Are Bosch O2 sensors ok?

Thanks for all the help!

Valentino

The Bosches will work fine, thats what I have

svopaul

Did you happen to drop or hit one of the O2 sensors against anything? Did you get anything on the sensor portion at any time(Anti seize? WD40? etc)?

Stix66

No I didn't drop it... but It is possible I could have gotten something on it. My friend was working on it with me so maybe he might have done somethingon accident. If that is the case it is ok, I am looking at it today I will re-install it and if that doesnt work I will get a new pair.

Stix66

I replaced the 02 sensors... the one that threw up the code had a rattle to it and I must not have noticed. I havent driven it long enough to see if it will throw a code again; if it does I will repost.

Thanks svopaul and others, and have a happy and safe 4th of July!