'96 Accord, VTECH, auto: replaced engine, hopefully have all wires and vacuum lines correct. Engine starts and idles just fine, can let it idle for 10-15-20 minutes and it still idles smooth as silk. As soon as I drive it a few yards the idle becomes really rough and drops to less than 500 RPM and stalls unless I keep some pressure on the gas pedal. The idle stays rough and very low until I shut it off and let it get stone cold. Then the proccess begins all over again, as soon as the engine warms to operating temp AND I drive it a few yards, the idle goes down and gets rough. This has me perplexed, I can idle it all day and it is fine, put the trans in drive and it goes BAD. Check engine light is on throws a PO135 code. Thanks, any help would be greatly appreciated.

 

code p0135 is for the primary heated o2 sensor,, you might want to chk it out

 

I may have found it, bad battery. Had to jump start it, this final time I left the charger on it while I ran it, it did not run rough after I put it in drive after it warmed up like every other time (I have it up on jack stands).