1991 5.0 Mustang Exhaust Concern

[5.0specialist]

Hello everyone. I have a 1991 mustang gt with BBK unequal length shorty headers, offroad X pipe, and steeda stainless mufflers that are identical to these, but used and a bit aged... : http://www.ebay.com/itm/Steeda-Muffl...dS7-QJ&vxp=mtr ) . I've noticed something weird when my car is idling. There is more air coming out of the driver's side tail pipe than the passenger side tailpipe. The driver's side tailpipe is also noticeably louder than the passenger side tail pipe. There are no exhaust leaks as far as I know (don't hear any leaks). The engine also runs great. No signs of a cylinder with low compression or a bad spark plug (recently changed my spark plugs using the recommended motorcraft plugs). The car runs great. Heck, it actually burns some rubber when flooring it from a dead stop with a stock AOD and 2.73 gears (it's also a convertible). These mufflers are made by Borla and are fully constructed with stainless steel. There is also noise insulation packing in these mufflers. Is this something I should worry about or is this just something that normally occurs?

Thank you,

Alexi

 

[Mustang5L5]

Take a rag and carefully stuff a tailpipe one at a time. Does the exhaust flow from the other one increase? Does the engine want to stall out.

Make sure said rag is clean and free from grease/oil


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[5.0specialist]

I'll try that today. Thanks

 

[5.0specialist]

I covered the driver's side tail pipe and a lot more air began flowing out of the passenger side tail pipe. The engine did not try to stall. Afterwards, I kept the engine at 2000 rpms (both tailpipes not covered) and my dad told me that there was still more air coming out of the driver's side tailpipe. I also noticed that the air on the driver's side is hotter than the passenger side. The X pipe still has the smog tube attached to the passenger side pipe before the cross over, which is capped by a rubber vacuum cap in the engine compartment where the smog pump hose was connected to. I wonder if that has something to do with it. This wednesday, I'm going to a mustang performance shop to get 3.73 gears installed. I'll have the guy check it out.

 

[Mustang5L5]

Got a laser thermometer? Shoot it at the mufflers. I'm thinking one of them may be blocked.


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[5.0specialist]

My dad has one at work that he can bring next week. Anyways, I'm getting gears installed this wednesday. I'll have the guy check it out. Thanks for your help.

 

[5.0specialist]

Had the gears installed today (wow, what a difference) and I took a closer looks at the exhaust. Everything is nice and snug without any leaks. I mentioned the mystery to the mechanic and he was confused by it. The steeda mufflers are made by Borla and they don't have any baffles (straight through design). What I'm thinking is that the packing in the driver's side muffler is more worn out allowing the muffler to be a bit louder and allow more air to bounce around in there and flow through. The car runs great and shows no signs of having any restriction in the exhaust.

 

[5.0specialist]

Well, I just used a laser temperature gun and the driver's muffler (the one that is louder and pumps out more air) is running at an average temperature of 260 degrees. The passenger side muffler (the quieter one with much less air pumping out) is averaging at 101 degrees. The pipes before the muffler (after the cross-over) have the same difference, although not as dramatic. Both pipes before the cross over read the same average temperature (240 degrees).

 

[5.0specialist]

Just found out what the problem was. There was a large piece of catalytic converter brick jammed into the flange of the x-pipe on the passenger side, where it meets the catback. lol Just had a 2.5 inch catback installed today (using Jones Max Flow mufflers).