Cars driving funny, please help!
 

I replaced the engine in my 96 accord EX. Now when I'm driving, if i'm not accelerating it's like i turned the key off. So I can't cruise at one speed because it will jerk forward then act like i cut the power, then jerk forward again. it does it in any gear. The check engine light is on and putting out codes for the IAC and the IAT. These are not bad however because I tried replacing them and it didn't fix it, so something else is causing these codes to come up and causing my car to drive like this.

did you use honda parts.

Yes, it was a direct engine replacement. I bought the engine from a wrecking yard, from a 99 accord with 37,000 miles. Had good compression and ran good wen they pulled it.

what ECU are you using.