Proof you don't need a tuner
Ultimate HDF Member
Joined: Jul 2011
Posts: 5,477
Likes: 5
From: New Braunfels, Texas
Not a good idea.
From the research I done prior to purchasing what I did was to look at facts not hear say or other bs and what I found was that a closed loop system is better than an open loop system. PC and all other tuners including xied are closed loop systems vs stock which is an open loop. If I can hook up all this and every thing runs like I want then no harm no foul
Just my .02
Just my .02
Road Warrior
Joined: Apr 2010
Posts: 1,739
Likes: 10
From: Suffolk, England
They aren't disabled as part of a PC installation because it makes your bike run better, its done because the piggyback nature of the PC would mean its settings would tend to be undone by having the O2 sensors still in play.
Grand HDF Member
Joined: Jun 2008
Posts: 3,983
Likes: 2,144
From: Ohio
Thing is, the O2 sensors do a good job of helping to maintain a good-enough AFR when you don't really need it any richer. If you disable them then you are assuming that the conditions on the dyno are the same as you will be riding at all times afterwards. The other sensors do help to adjust but to disable a major component of the engine management is not necessary or even a good idea.
They aren't disabled as part of a PC installation because it makes your bike run better, its done because the piggyback nature of the PC would mean its settings would tend to be undone by having the O2 sensors still in play.
They aren't disabled as part of a PC installation because it makes your bike run better, its done because the piggyback nature of the PC would mean its settings would tend to be undone by having the O2 sensors still in play.
Outstanding HDF Member
Joined: Dec 2010
Posts: 2,036
Likes: 8
From: Temecula, CA
EFI does away with that for the most part. While it is still important to tune the vehicle where you will ride it most, the EFI system will now adjust for temperature and barometric presure automatically. If the bike runs good at sea level, it's going to run good in Denver too. If you take away the ability to use O2 sensors, part of it's ability to do this is lost.
Seasoned HDF Member
Joined: Aug 2010
Posts: 5,173
Likes: 177
From: East Coast
Stage II A/C
Complete set of pipes, 2:1, no cats
Completely stock 96" engine
No tuner of any kind, not even XIED
Some decel pops, mostly just gurgling
Bike runs really strong, made the factory set up feel like it was an 883
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Supporter
Joined: May 2011
Posts: 627
Likes: 2
From: Salem, OR
On my 2011 Fat Bob 2-1-2 I recently put cycle shack baffles in my mufflers, and from the feel of the heat coming off the pipes and the look of the plugs it was running too lean. I already had a Screaming Eagle heavy breather on it before I modified the exhaust. No tuner, no download, no xieds.
Last week I switched to an older cat'less head pipe and figured I should get some xieds, which I did, so it would run richer. Turns out the xieds made it too rich with no cat, a freer flowing baffle setup, and a SE air intake. When I would stop I would sometimes get that bogged down sensation in the throttle followed by a backfire and from my years of working on hotrods and Jeeps I knew that is typically too rich of exhaust. I was getting a lot of rather loud decel pop and occasionally a bang from backfire. I also had a few occasions of the bike not turning over on the first try when I hit the starter button. Again, my experience led me to believe to rich on the fuel. This all happened within 100 miles of riding over a couple of days.
So I pulled the xied's and disconnected the battery for half an hour to allow for a reset of the ECU (which most people forget to do when making major modifications to fuel or exhaust). Then took the bike out for a 40 minute ride to allow for the FI to adjust the fuel control to where it senses it should be. Now it runs great with very little decel pop and fires up every time. Runs really good and sounds loud and mean. Made sure to clean the plugs in between too so I will keep and eye on them to see if they get corroded or fouled up from the changes.
Last week I switched to an older cat'less head pipe and figured I should get some xieds, which I did, so it would run richer. Turns out the xieds made it too rich with no cat, a freer flowing baffle setup, and a SE air intake. When I would stop I would sometimes get that bogged down sensation in the throttle followed by a backfire and from my years of working on hotrods and Jeeps I knew that is typically too rich of exhaust. I was getting a lot of rather loud decel pop and occasionally a bang from backfire. I also had a few occasions of the bike not turning over on the first try when I hit the starter button. Again, my experience led me to believe to rich on the fuel. This all happened within 100 miles of riding over a couple of days.
So I pulled the xied's and disconnected the battery for half an hour to allow for a reset of the ECU (which most people forget to do when making major modifications to fuel or exhaust). Then took the bike out for a 40 minute ride to allow for the FI to adjust the fuel control to where it senses it should be. Now it runs great with very little decel pop and fires up every time. Runs really good and sounds loud and mean. Made sure to clean the plugs in between too so I will keep and eye on them to see if they get corroded or fouled up from the changes.
Advanced
Joined: Feb 2011
Posts: 78
Likes: 0
K&N Air Cleaner and 2:1 Vance and Hines with no tuner and RARELY has it backfired. K&N, on its own though, made my bike seem soo much faster, once the 2:1 went on it seemed to have slowed it down. So IDK, I guess I need a dyno, but its expensive!