2010 FLHXXX Trike with a 103 and SE Stage 1 upgrade with Cobra slip-ons, Power Commander V tuner...

Before any modifications, the engine would occasionally stumble and cough with increases in throttle and backfires when down shifting, maybe 75% of the time. There is also a strong gas smell. It still stumbles after the modifications and putting on the PCV but after it stumbles, it pulls real strong. The higher the RPM, the less likely it happens.

Any thoughts on this? Injectors?

 

Connected to the top of the throttle body will be a black rubber vacuum line, make sure that it's securely connected at both ends. Sometimes they split with a little age and slip off.

 

I forgot to mention that there were and are no error codes being thrown...

Update: Found that the PCV was shipped without a MAP installed. Downloaded and installed a base MAP and now it runs 99.9% better, but still has some coughing with quick throttle increases at times...

 

too lean..."at times"
you may need to increase the accel pump ...
good luck...
https://www.hdforums.com/forum/sport...l#post18267672

 

UPDATE: My friend gave up and took it to Republic in Stafford Tx...Tech found broken wire to the cylinder head temp plug and the front O2 sensor bad. He says that his Trike runs like he thinks a 103 Stage 1 should run now. I didn't ask him how much it costs...

...still doesn't explain no codes...

Thanks for all the suggestions...

 

The 03 does not have 02 sensors stock. If the head temp sensor is out of cal, code will not be thrown.

 

Refer to the first sentence in my opening post...

It is not my bike, it is my friend's 2010 FLHXXX Street Glide Trike.

 

OK..

Head temp sensor out of cal will not throw a code but since it screws up the mixture, it could throw a 02 sensor code.