98 Accord A/T F23A1 is stuck in limp mode after head swap, it goes to 4k rpm and redlines and when in drive when it hits 4k feels like it lost fuel and wont keep going.

it has one code stored and is for heated o2 sensor which i doubt would put it in safe mode.

what do u guys think?

 

If the primary O2 is bust, with OBDII cars the PCM will protect the catalyst and pull timing/fuel to not damage the catalyst. If the O2 is faulty, replace it to regain your lost POWA!

 

yeah but that is not the problem with LIMP MODE.

 

Nops O2 does not put car in Limp mode. I know this for a fact because recently I had experiments with my F23A ECU which i have spare now. Did you checked for Service Check Connector?

Check if your VTEC solenoid is plugged in.

 

where is the Service Check connector! I was looking all over for it today when using my timing light.

 

It is on passenger side. Google for your car or watch EricTheCarGuy on youtube he has video on how to pull and read codes