Mustang Evolution Forum banner

1 - 19 of 19 Posts

·
Registered
Joined
·
3,551 Posts
Im buying a used magnaflow x pipe for 250 I already have GT500 axelbacks will this make A big sound difference?
if it is the cat delete one and you actually delete the cats yes. Else wise not really. Sound might be a small bit raspier. Will not be louder.
 

·
Registered
Joined
·
3,551 Posts
Thats it the offroad x pipe
yeah if you use the whole thing, including the down pipes without cats, 100% worth the money. You car will get really loud on WOT but with the GT500 axle backs not be terribly loud at cruising.

If you keep the stock car downpipes with the catalytic convertors, not worth it so much. Your car will not get louder but will be raspier.

If you do take the cats off but don't tune your car, you will throw CEL codes.
 

·
Registered
Joined
·
3,551 Posts
Is there A way to get around tuning it dont want to.void warranty
no, you'll throw CEL codes always when the car is on as the 02 sensors will detect that the cats are not "working." The car will still run fine, but you'll always have the check engine light on. With a tune the 02 sensors can be turned off so this doesn't happen.

also removing the cats technically voids your warranty too. It is technically illegal to remove them, but many of us live in places that don't do EPA checks so we don't have to worry about it. Other people have people that will "pass" them so they don't have to worry about failing emissions checks.
 

·
Registered
Joined
·
35 Posts
no, you'll throw CEL codes always when the car is on as the 02 sensors will detect that the cats are not "working." The car will still run fine, but you'll always have the check engine light on. With a tune the 02 sensors can be turned off so this doesn't happen.

also removing the cats technically voids your warranty too. It is technically illegal to remove them, but many of us live in places that don't do EPA checks so we don't have to worry about it. Other people have people that will "pass" them so they don't have to worry about failing emissions checks.
I would also say that tuning your car after significant modifications is NOT just to keep your car from throwing an engine light. If u make modifications to the exhaust and remove the cats, the car NEEDS to be tuned to correct the air/fuel ratio. You could actually do damage to your engine if you choose not. You will also squeeze a few more HP and improve throttle response.
 

·
Registered
Joined
·
3,551 Posts
So you happen to know if Texas does those checks
You'd know if you do. You'd have to once a year take it to a station and have it very emissions. Some places do a visual check all places do a sniffer test. I don't think Texas does but not sure.

---------- Post added at 05:19 PM ---------- Previous post was at 05:17 PM ----------

I would also say that tuning your car after significant modifications is NOT just to keep your car from throwing an engine light. If u make modifications to the exhaust and remove the cats, the car NEEDS to be tuned to correct the air/fuel ratio. You could actually do damage to your engine if you choose not. You will also squeeze a few more HP and improve throttle response.
My understanding is this is not correct for the 5.0L engines. They do see somewhere in the ballpark of 15-20HP gains but I was told more than once that removing the cats with the 5.0L engine only throws a CEL code. Not that you wouldn't want to tune it, but the car automatically adjusts to the cats "failing"
 

·
Registered
Joined
·
3,783 Posts
Emissions testing is coming to every state. You can thank the young punks with diesels, that think It's cool to blow black smoke everywhere.
 

·
Registered
Joined
·
3,551 Posts
Emissions testing is coming to every state. You can thank the young punks with diesels, that think It's cool to blow black smoke everywhere.
oh yeah? Have sources? They have tried to bring E-Check to my area a few times and been told to GTFO every time by a huge margin.
 

·
Registered
Joined
·
3,783 Posts
nosympathy said:
oh yeah? Have sources? They have tried to bring E-Check to my area a few times and been told to GTFO every time by a huge margin.
It's coming just like helmet laws. When the Feds pull the road money, everyone will cave.
 

·
Registered
Joined
·
35 Posts
You'd know if you do. You'd have to once a year take it to a station and have it very emissions. Some places do a visual check all places do a sniffer test. I don't think Texas does but not sure.

---------- Post added at 05:19 PM ---------- Previous post was at 05:17 PM ----------



My understanding is this is not correct for the 5.0L engines. They do see somewhere in the ballpark of 15-20HP gains but I was told more than once that removing the cats with the 5.0L engine only throws a CEL code. Not that you wouldn't want to tune it, but the car automatically adjusts to the cats "failing"
I'll do some research. So your saying that when the ECU detects that the factory catted H-pipe is removed and throws a code, it automatically 're-maps itself to compensate for the high flow back end?
 

·
Registered
Joined
·
3,551 Posts
I'll do some research. So your saying that when the ECU detects that the factory catted H-pipe is removed and throws a code, it automatically 're-maps itself to compensate for the high flow back end?
I honestly am not sure on the details. I was advised by American Muscle and a few big time members on here when I switched to my O/R X that if I didn't have a tune for that it would still run fine, but I would just throw codes. I was told that being tuned for it would allow the better flow to be utilized. I never ran it like this though as I had new tunes from AM/BAMA come in the day before I installed my o/r x.

I have come to learn that these 5.0 engines are very odd in how they work. We get a lot of 4.6L guys in here who find it odd because certain things with the 5.0 confuse them. My understanding on the 4.6 is removing the cats doesn't increase your power any, but it does on the 5.0 when they are removed. The 5.0 seems to just absolutely love no real back pressure.
 

·
Registered
Joined
·
441 Posts
if it is the cat delete one and you actually delete the cats yes. Else wise not really. Sound might be a small bit raspier. Will not be louder.
I had the magnaflow true xp and it was very loud, and I loved how loud it was but it was also very raspy, and I hated the sound of that..just my two cents.
 

·
Registered
Joined
·
453 Posts
I'll do some research. So your saying that when the ECU detects that the factory catted H-pipe is removed and throws a code, it automatically 're-maps itself to compensate for the high flow back end?
it is my understanding that the front O2 sensors (wideband) are used by the PCM to adjust AFR, and rear sensors are mainly to determine cat function and are not used for engine performance. Thus, they can be safely turned off.

You won't hurt the engine by removing the cats and NOT disabling the rear O2 sensors .. but you'll have a code all the time.

That's my understanding, anyway. I could be wrong.
 
1 - 19 of 19 Posts
Top