Magnaflow

[bstroble]

I have a 1995 GMC sierra 5.7 and i put a 3 inch Magnaflow on it. Im trying to get the lowest/deepest sound possible with it still sounding good but not obnoxious. What would you guys suggest to do? all i did was muffler back so would you guys remove the cat or what? will try to post a video later of the way it currently sounds. Any advice will help!

[Carder09]

Removing your cats will probably make it a tad bit louder actually.

[bstroble]

will it make it any deeper and throaty-er? or just loud and obnoxious. right now at low rpms it has a nice grumble but once it hits higher rps(2200) it begins to sound almost like stock. also if i remove the cat how will effect the truck?

[scooby5121]

remove the cat and all your after cat sensors will screw your computer up and engine light on throwing codes..... etc.

Good luck and put black tape over the instrument cluster to hide all the red lights .

[bstroble]

so taking the cat off will screw with computer stuff? does it hurt the truck at all or will it just send off lights

[bstroble]

Or also what about just switching the stock cat for a magnaflow 3" in 3" out high flow cat?

[scooby5121]

so taking the cat off will screw with computer stuff? does it hurt the truck at all or will it just send off lights

make the computer tell the engine that you are running lean/rich.......etc. Thus screwing the engine performance and gas milage.

 

just imagine taking the computer to your pace maker on your heart and cutting a wire !!!!

[kstruckcountry]

If your truck is a 95 you can usually put a spacer on the exhaust sensor and it won't set off any lights, or you can get sensor foolers. You're not going to gain anything by taking them off though, and you're not going to see anything by putting on high flow cats either, they don't really make a difference.

However, like a said if your truck is a 95 it's not going to miss them.

[bstroble]

So in all reality id be better off just keeping my current set up the way it is with stock cat and magnaflow muffler?

[kstruckcountry]

Yes, removing cats would make it higher pitched if anything. Some headers might provide a lower sound though.

[bstroble]

How much would headers run and will they add any performance?

[Chris]

What length is the case on the Magnaflow? If it is an 18" or 22" you could step down to a 14"

[scooby5121]

How much would headers run and will they add any performance?

Headers can add up, yes they add performance , and yes they sound nice.

Lots of different manufactures of headers. Prefer the aluminium dipped headers on my 79 Camaro. (Black-Jack)

Scooby

[TJay74]

make the computer tell the engine that you are running lean/rich.......etc. Thus screwing the engine performance and gas milage.

 

just imagine taking the computer to your pace maker on your heart and cutting a wire !!!!

 

This is wrong to some degree, while it will trigger a SES light it wont affect performance as the 2 sensors after the cat are only there to tell the ECM that the converters are working, they have no bearing on fueling changes. That is all handled by the before cat O2 sensors.

[scooby5121]

This is wrong to some degree, while it will trigger a SES light it wont affect performance as the 2 sensors after the cat are only there to tell the ECM that the converters are working, they have no bearing on fueling changes. That is all handled by the before cat O2 sensors.

Thanks Todd, I read it wrong.

Great Catch !!!!