I got my ECU that is chipped to run LS/Vtec from phearable.net but it idles VERY rough and low and I can floor it and it will only go to like 800 RPMs.....The most I can get the RPMs up to is like 2500 and thats with pumping the gas pedal over and over. The car runs smooth with a stock P28!!! The car is using a GSR engine harness and only has one O2 sensor where the cat conv. used to be.....the only code its throwing is primary O2. I know the P28 Vtecs only use one O2 so could this be the prob?? Should I need the Primary O2 to run correctly or does this seem like some kind of other sensor. The guy I got the car from had a chipped ECU as well and he said it ran rough, thats why he installed the P28....does anybody know whats so different about the P28 that would make it do this??

 

get it tuned or put a gsr ecu in it

and its not the o2 its the chip

 

have you checked to see if your throttle body is properly opening? have you checked TPS? i have been running a phearable.net ECU for over a year now and have not had any problems with it.

 

check tps, is timing right?