(split) What is PAIRS system?

Harper: I'm not familiar with the acronym PAIRS. As I'm not sure to whom your question was directed, please excuse the intrusion if you were referring to another member.
Either way, I'm still interested in knowing what a PAIRS system is.

PAIR System:

AIR INDUCTION SYSTEM
The air induction system (AI system) introduces fresh air into the exhaust port in order to burn the
unburned gas (which is present in the exhaust gas) in the exhaust pipe. The burning of the
unburned gases in this manner enhances the efficiency of the catalyst and results in cleaner
exhaust gases.
The AI system takes a portion of the air from the air cleaner, sends it to the reed valve via the air
cut-off valve, and introduces it directly into the exhaust port through the reed valve.
The air cut-off valve is controlled by the signals from the ECU in accordance with the combustion
conditions. Ordinarily, the air cut-off valve opens to allow the air to flow during idle and closes to cut
off the flow when the motorcycle is being driven. However, if the coolant temperature is below the
specified value, the air cut-off valve remains open and allows the air to flow into the exhaust pipe
until the temperature becomes higher than the specified value.
The reed valve is provided on the cylinder head cover above the cylinders, and sends air to the
exhaust pipe through the inside of the cylinder head.

Pulsed Secondary Air Injection System (or passive, I have seen both)

Hoses etc. on top of the engine to dump air into the exhaust to help burn off hydrocarbons before they are emitted. Removal doesn't affect operation but cleans up the top of the engine to some extent and may reduce "popping" upon deceleration.

Fred's faster (and much wordier) than I am.

Welcome to the forum. I have a good buddy down your way. We'll have to hook up for a coffee next summer.

Canadian FJR

What does PAIR mean.... have you ever heard the admonition, "sound off like you have a pair"? Well, there ya go.

RossKean said:

Fred's faster (and much wordier) than I am.

Click to expand...

Cut 'n Paste. Cut 'n Paste.

Thanks Fred for the well defined essay. Am I correct to believe the Harley guys do away with the catalytic converter and thus the raw gas smell they spew on us when we get behind one of their noise makers? Is there any performance gain by doing away with the PAIR? I referring to the PAIR on the bike, not my pair!!!

The injected air is into the exhaust so the additional combustion (or lack thereof) at that location won't do a thing for performance. It might diminish popping on deceleration and will result in higher hydrocarbon and possibly higher carbon monoxide emissions. The main reason for removal of the PAIR system is to improve access to the top of the engine. Much easier to open it up for valve checks, do TBS service and change plugs.

Yes, this ^^^.

Removing the PAIR plumbing and valve just gets rid of some engine bay clutter and cleans up under the tank. The ECU will not even detect it being missing. Removing it will reduce the exhaust popping on deceleration, which is a function of the injected air and fumes combusting. You don't hear it that much with a stock exhaust, but it's there even on my 2014, and much more noticeable on bikes with aftermarket or trooper modded mufflers. The only time the PAIR is injecting air is at idle and on over-run (deceleration) . When you accelerate or cruise it is not doing anything.

Removing the cats entirely, from the header pipes, and from the exhaust cans (on 2nd Gens only), will reduce the back pressure and may produce some limited gains in top end power. Of course once the cats are gone the PAIR does nothing except produce backfires.

BTW - My "essay" was a direct copy and paste from the FSM description of the PAIR system.

Dale2010 said:

Harper: I'm not familiar with the acronym PAIRS. As I'm not sure to whom your question was directed, please excuse the intrusion if you were referring to another member.Either way, I'm still interested in knowing what a PAIRS system is.

Click to expand...

I just saw this. Fortunately several others answered your question. I was addressing the OP (in the thread from which this was split) but didn't realize that the thread was almost a year old.

My ecu noticed it missing on my 2016

Hmmm... good to know. I don't think any 3rd Gens prior to 2016 would notice the missing solenoid, but they did make some changes in 2016 as that was the first year of the OBD2 port connection.

Prestone said:

My ecu noticed it missing on my 2016

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So what did you do? It would be good to know.

Dave

<blockquote class='ipsBlockquote'data-author="Prestone" data-cid="1350169" data-time="1482166367"><p>

My ecu noticed it missing on my 2016</p></blockquote>

Did it set a code?

Took the your plates off and now they are sitting in my tool box. It kept throwing a check engine light. I'm pretty sure the code was P1400. The bike seemed to run fine with them on though. I never tried leaving the solenoid valve in. That might of fixed it.

Yeah, I suspect that would be what the ECU would detect; the missing solenoid. So maybe you'd need a resistor pack on the 2016 and later models to fool the ECU into thinking the PAIR is still there?

Has anyone done a PAIR removal on a 2014 or 2015? Ive got the plates but the garage is too darned cold to do the valve check and PAIR removal I've planned...

Allen_C has pair plates on his 14 I believe.

Right, but the 16 is the first FJR to have an OBD II system. It's diagnostics are different from the other bikes.

One of the first things I did to my '14 was to replace PAIRS with Winnpro block-off plates. No codes, no issues of any kind. Did that right after installing new exhaust cans.