Car is running like ***...very rich, high idle, cant go over around 4k rpm...its throwing a CEL but it doesnt display a code. This is with a chipped p28/hondata...would a bad ECU cause this problem?

 

If you jump the harness and there is still a solid CEL, this usually means the ECU board itself is malfunctioning somehow.

Remove the ECU cover and cut the jumper labeled "J1", this reverts the ECU back to its original state (before chipping) and if the problem lies with the Hondata chip or any of the soldering done to the circut board the CEL will dissapear. If the CEL is still there the problem is not the chip or any of the soldering done in the chipping process, but rather the actual ECU board itself.

If you don't feel comfortable cutting the jumper, you can always try a different ECU.

 

cut j1, shes back to stock. i bought this advertised ecu as a VIRGIN p28, but when I got it, it was nothing of the sort. probobly the worst chipping job ever done on an ECU. I tried to fix it the best I could, but I guess it was all in vain...