Suzuki GSX-R Motorcycle Forums Gixxer.com banner

1 - 11 of 11 Posts

·
Registered
Joined
·
19 Posts
Discussion Starter #1
Hi Everyone. So last night I install my Yoshi R77 slip on without DB killer and cat delete pipe. The bike now idol unevenly. The rpm go up and down between 1000rpm and 1500rpm. I think this is due to lesser exhaust compression due to the removal of the cat. Does anyone have a fix for this? I have pay a lot of money for the Yoshi and the bike sound incredible so I do not want to make the bike stock again. I will appreciate any advice.
 

Attachments

·
Ex-Lady Supermod
Joined
·
16,100 Posts
Did you install a PC or had your ECU re-flashed? If not you need to for the bike to run properly and get the maximum out of the Yoshimura/bike.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #3
Did you install a PC or had your ECU re-flashed? If not you need to for the bike to run properly and get the maximum out of the Yoshimura/bike.
I have not install a PC or had the ECU re-flashed. I was told it is not nessesary with a slip on only when I do a full 4 into 1 system.
 

·
Premium Member
Joined
·
73,190 Posts
If you remove the cat you need to re-map the bike, be it through an ecu flash or a piggyback unit.
 

·
You should listen to me. No, seriously, listen to
Joined
·
7,708 Posts
Did you disconnect the HO2 sensor or do anything that affected the ISC? Disconnected vacuum hose?
 

·
Registered
Joined
·
19 Posts
Discussion Starter #6
Did you disconnect the HO2 sensor or do anything that affected the ISC? Disconnected vacuum hose?
I had to remove the Lambda sensor from the cat and screw it into the link pipe to avoid error codes. Refer to picture attached of the link pipe. What I found is when the bike idol and I block the exhaust opening a little but with my hand then the bike idol normally. It seems as if my bike do not like so little back pressure. I have order a DP killer that will add a bit back pressure so hopefully this will help. This actually sucks because the bike perform and sound stunning with the Yoshi R-77 pipe without the DP killer. The DP killer takes away about 4db and also reduce HP. I was hoping that with the Lambda sensor still in tack the bikes ECU will adjust itself after a few kilometres. I guess not unless you first need to drive a few hundred kilometres.
 

Attachments

·
You should listen to me. No, seriously, listen to
Joined
·
7,708 Posts
You might try blocking the PAIR valves, if not already done. There are ways of doing this that are crude but quick and easy - like plugging the air supply line with a marble.

Also I wonder if you might have an exhaust leak somewhere in the vicinity of the HO2 sensor that's allowing air to be pulled into the system at idle. Check the various joints. You might also try looking at the HO2 sensor output per 1A-106 of the service manual to see if it's moving around. I'm unaware if newer versions of SDS display such information.
 

·
Registered
Joined
·
265 Posts
I think this is due to lesser exhaust compression due to the removal of the cat. Does anyone have a fix for this?
yes it is this. the exhaust backpressure is all different to what the bike is expecting causing the uneven idle (and more difficult starting too probably). The Air-fuel ratios will also be off all through the rev range too...
you need an ecu remap to sort this.
otherwise, if you put the DB killer into the exhaust it should help as it will also increase backpressue (it wont fix it though).
Beyond this, until you get an ecu tune, just put the cat convertor back in and leave the Yoshi pipe on (if you can) as it is the cat that creates most of the back pressure. that way you get some good Yoshi sound but without the bad running :)
 

·
Registered
Joined
·
19 Posts
Discussion Starter #10
_єℓ_иιñσ_ℓσ¢σ_;8844801 said:
You can also adjust the idle a little bit higher. With these bikes i think it's also an idle screw on the left side on the bike. But im not sure.

From 2009 no idle screw. Idling is all electronic.
 

·
Registered
Joined
·
19 Posts
Discussion Starter #11
My DB Killer finally arrived yesterday. I have install it and the idling is back to normal now with the additional back pressure that it cause. Must say it does not silent the bike as much as I have expected. It still sound pretty good with the Yoshi R-77 and cat removed. Once I have a few buck available I am going to install a PC5 or Bazzaz and then remove the DB Killer permanently. However for now this will have to do.
 

Attachments

1 - 11 of 11 Posts
Top