Yoshimura pim2 efi troubles

I installed a Yoshimura Pim2 on a 2009 WR250X and it fired right up and ran great but the check engine light was on. I contacted Yoshimura and they said they had never heard of such a thing but recommended that I disconecct the battery and see if that would help. Now the bike wont start or when it does it runs pretty much like it did before I installed the pim2 and the cel is still on. It has a yoshi slip on and k&n filter. In the instructions it asks to remove the air pressure sensor (1 bolt) and disconnecting the hose and reconnecting it after installation. But there is no picture or diagram of said sensor and the yoshi techs dont know where it is either. I am at a loss here folks. The yoshi system is a closed loop and requires a lot of connections. There are no open connectors when finished. The power commander is much easier to install ( I'm doing this for a friend who ordered the pim2). Any ideas or suggestions would be appreciated. Thanks

Has the EXUP servo motor been removed?

Did you do anything else besides install the thing-a-ma-jig from Yosh?

Was it part of a bunch of things you did all at once, or did you just install that one thing?

this thing-a-ma-jig <-- clicky????

Thanks for responding. The EXUP motor is still on the bike and hasnt been messed with as far as I know. I didnt do anything to the bike other than remove the side panels, gas tank and radiator shrouds and then routed the wiring harness through and made the connections step by step. The PIM2 module came loaded with a map for the slip on. Whats happening now is the bike will sometimes start and run ok, like it did before installing the pim2 and then when I try to start it again it just wont fire. And the cel is still on. I'm going to take it down to a local shop and have him look it over. It could be a kinked wire or hose or something of that sort. I am really worn out trying to figure it out. My friend lost the owners manual so I dont know how much info I could have had access to but I suspect the air pressure sensor is listed in it. Thanks again

So the full exhaust system was on the bike and it was running fine with no CEL for some period of time before the Yosh doo-dad was installed?

If that's the case I'd guess it's not the EXUP servo motor error light.

I have to wonder if there's a vacuum hose not connected properly somewhere.

Yes Motokid, It was running fine with the slip on and k&n filter although it had some hesitation for about two minutes till it was warmed up then it would run fine except for an occasional stall out at a light that I blame on the stock fuel injection combined with the added flow from the air filter and yoshi slip on

So before you dump a ton of money into having a dealer sort it out.....can you remove the Yoshi doo-hickey and see if the CEL goes away?

Yes, Im going to go through it and even reconnect the stock plugs and look for anything that may have come loose. What is puzzling to me is how it ran so good after I installed it. It was mean. Very crisp throttle response, more power, a little louder and very linear powerband. But that darn light was on so something has to be wrong. You're right about having to dump money into it I dont want to do that even though my friend wants to pay it's a matter of pride for me. The pim2 module itself could have a glitch. It is designed so that a data box can be attached for super fine tuning so it is pretty sophisticated.