Fairly elementary exhaust question

[dlaude]

Okay I could have sworn that I read somewhere that if the stock h is replaced the check engine light will come on. I've searched and searched but can't for the life of me find that info again. I'm not sure why the CEL would come on with the stock cats still there, so there's a good chance I mis-read it whilst drunk or had a bad dream lol. Anyway, I'm thinking I'm going to go shorties and catback, and keep the stock cats. That won't get me a check engine light, correct? Also, I won't NEED a tune for this combination, correct? TIA.

 

[turbosha]

if the cats stay. a cel shouldn't come on.
I ran with out resonators and straight thru(steeda) axlebacks with no issue.

 

[Nuar]

Yup, as stated, the cell will come on only if cats are removed.

 

[dlaude]

Okay cool, since that's how all other mustangs I've owned have been, that's what I thought, I have no idea where I got those crazy ideas from lol.

Also, I won't need a tune for shorties and catback, right? (though I know some would recommend one).

 

[Lethal302]

Okay cool, since that's how all other mustangs I've owned have been, that's what I thought, I have no idea where I got those crazy ideas from lol.

Also, I won't need a tune for shorties and catback, right? (though I know some would recommend one).

Nope won't NEED it

 

[nicksender]

I didn't think there was any power to be had adding shorty headers or even an aftermarket cat h/x pipe to new 5.0's?

I thought any meaningful gains would come from LT's and/or off-road pipes?

 

[Lethal302]

I didn't think there was any power to be had adding shorty headers or even an aftermarket cat h/x pipe to new 5.0's?

I thought any meaningful gains would come from LT's and/or off-road pipes?

You're right...I personally wouldn't bother with anything else

 

[dlaude]

I didn't think there was any power to be had adding shorty headers or even an aftermarket cat h/x pipe to new 5.0's?

I thought any meaningful gains would come from LT's and/or off-road pipes?

Correct, there is very little power in any exhaust changes in these 5.0s. I've seen comparisons where someone goes from a set-up I mentioned to a long-tube, high flow cat set-up and gain just a handful of hp. The increase from completely stock to long tubes, off-road, and straight through mufflers (presumably 'higher flowing' than chambered) isn't as much as you'd think. All things the same before and after the swap, I'd be surprised if it was 15hp.

 

[dlaude]

I have no idea where I got those crazy ideas from lol.

I THINK I got that idea from reading about people getting a code with long tubes and catted X/H pipes. I'm finding some issues along those lines, so maybe that's what I was thinking when I started this thread. With the stock cats I gotta believe that there won't be an issue.

 

[Carbd86GT]

Okay I could have sworn that I read somewhere that if the stock h is replaced the check engine light will come on. I've searched and searched but can't for the life of me find that info again. I'm not sure why the CEL would come on with the stock cats still there, so there's a good chance I mis-read it whilst drunk or had a bad dream lol. Anyway, I'm thinking I'm going to go shorties and catback, and keep the stock cats. That won't get me a check engine light, correct? Also, I won't NEED a tune for this combination, correct? TIA.

If you just replace the H section and the stock cats stay, the CEL will not turn on and no tuning is required.

Correct, there is very little power in any exhaust changes in these 5.0s. I've seen comparisons where someone goes from a set-up I mentioned to a long-tube, high flow cat set-up and gain just a handful of hp. The increase from completely stock to long tubes, off-road, and straight through mufflers (presumably 'higher flowing' than chambered) isn't as much as you'd think. All things the same before and after the swap, I'd be surprised if it was 15hp.

There is actually very good power to be had in the 5.0L's. The stock cats flow fairly well, so just switching to a mid-pipe with high flow cats may not show much gain, but we picked up 14 rwhp by going with just our off road X pipe and NO tuning. This route will turn on a CEL for most cars without tuning. Switching from completely stock to long tubes with an off road pipe can pick up 30+ rwhp. If you already have an off road pipe then add long tubes, then yes, your gains won't be as great unless the car is making big power.

 

[dlaude]

If you just replace the H section and the stock cats stay, the CEL will not turn on and no tuning is required.

Okay, that's what I thought, thanks.

There is actually very good power to be had in the 5.0L's. The stock cats flow fairly well, so just switching to a mid-pipe with high flow cats may not show much gain, but we picked up 14 rwhp by going with just our off road X pipe and NO tuning. This route will turn on a CEL for most cars without tuning. Switching from completely stock to long tubes with an off road pipe can pick up 30+ rwhp. If you already have an off road pipe then add long tubes, then yes, your gains won't be as great unless the car is making big power.

Yes I found some more concrete evidence showing my estimate was a bit under. Thanks for the info.