I have a 07 Street Glide and have only added V&amp\\;H Ovals (air cleaner is original and no remap). I have put about 50 miles on the bike and inspected the plugs and they are ashy in color. Additionally, I noticed the rear piston "y" header was glowing orange when I pulled the bike in the garage (after idiling for about 30 seconds to a minute after a ride). Also, I noticed the exhaust pressure and temperature coming out of the left side pipe is much less than the pressure and temperature coming out of the right side pipe.
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From what I have read, the ashy colored spark plugs and orange colored "y" header pipe are signs of an enging running lean. Should the engine have leaned out to a dangerous level by the install of just the slip-on pipes?&nbsp\\; Also, is it normal for the pressure and temperature of the left side pipe to be much lower than the pressure and temperature of the right side pipe?&nbsp\\;&nbsp\\;&nbsp\\;

 

The stock headers are very close to being a 2-into-1\\; easily 75% of the exhaust goes to right pipe.
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Can't help with the orange Y-pipe\\; if it was my bike I'd put it on a dyno just to check AFR.

 

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Sorry I keep loosing the post...I give up

 

The 07's run lean from the factory and with any change to the exhaust will only make the problem worse. Do yourself a favor and add a stage 1 air filter and have your ECU remapped or add a separate fuel management system such as a Power Commander III. Your bike will run so much better and without the heat problem caused by a too lean mixture. I have the V&H 2 into 1 exhaust, Arlen Ness Big Sucker 2 Air cleaner and a PCIII fuel management system. Bike has much more power and get 48 mpg highway and 43 city. Oh, it is an 07 Road Glide.