I have a 94 Honda Prelude. It started running like crap a couple days ago. I recently put in a new timing belt, did a h23 tensioner swap to it. It has ran perfect for the last three months, I replaced the spark plugs, distributer cap and rotor last month. Now when I drive it and it gets to normal running temperature it throws a check engine light and then starts running like crap, it runs fine cold but when it gets warmed up to normal temp it throws a check engine light and hardly runs... timing is perfect, all fuel injectors are working, all the wires are getting spark, i left it running while it was running like crap, pulled out the third and fourth spark plug wire and it made no difference weather they were in or not...it runs fine if you are past 3500rpms anything lower than that it chugs and hesitates and it hardly idles! I need help! Can anyone think of what would be wrong with it?

 

What check engine error? It'll tell you all.

 

The check engine light just pops up on the dash after letting it warm up to normal runnign temp and then all of a sudden it runs like a pile. I don't know how to do a diagnostic on it...I tried looking for the diagnostic port under the dash but couldn't find it..it's under the dash on the passanger side and it's a blue plug correct? if so, i didn't see it...

 

behind the radio from the drivers side.

 

i did a diagnostic, pulled up throttle positioning sensor ivac or ecm and egr valve, i cleaned out the egr valve and the ivac and i have a new blox throttle positioning sensor adjusted correctly, i put a new distributer in, a new egr valve too, so what would be making my car idle so bad..