I have a ek with a b20 swap on a obd2 p75 ecu I know its gonns run lean with the ecu but whenever its cold my afr is about where its suppose to be but after it warms up and anything under half throttle im running a 17.0 afr- no cel and ive tried my hondata with many different bases. Any ideas ht?

 

No one?

 

what year ek are we working on? what year b20 do you have? I never had problem with it running lean when i had my b20 in my ek, drove like normal. does the car choke at a certain rpm? Are you sure you have no check engine light? Have you done anything to your car recently? Did this just occur?

 

After 4500 all my power is there but until then its lean.

 

If there is no load, this is fine, if you are letting off or coasting slightly this is not lean, if there is load even at partial throttle for example lightly taking off from a stop sign it should b closer to stoich.