ok, so i just put a S5 13b in my first gen. it sputters under load at any more than 1/4th throttle and bogs in neutral.



i've just put on a new MAF, and the fuel pump is new too. any ideas?

 

Completely factory S5 motor? Injectors, everything? OEM S5 ECU running the car?

 

correct

 

I'm not sure what you mean by bogs in neutral. What are the circumstances? You can't rev the car in neutral?





First thing I would do is test the TPS sweep with a multimeter to make sure it's functioning properly. If you're not sure how, you can unplug the TPS and run it. It will send the computer into a fuel map to deal with a failed TPS. See how it runs. Does it make the situation a little better, or alot worse?