arite, i have a p28 with a mugen chip in it. I put it in my car to test it out and it ran fine. i took it out again because it was using up too much gas. i put bak my p72 check to save some gas, but then i put back the p28 again cause i got bored, when i put back the p28 i pulled a check engine like which was (21) vtec not workin. I put bak my p72 and it didn't pull a check engine light. What could be wrong with the ecu?

 

did you make sure all your plugs were totally pushed/plugged in?

 

yes...i did it two times..bak and forth from the p28 to the p72...the p72 alway worked fine but p28 pulled a code.