Car lags whenever, no special conditions needed. I can hold the gas at 2k going 40mph and all of a sudden i feel it lag, Putter sound then slows down, And throttle response delay. Mainly happens when im trying to keep a steady cruise speed. Then if i add a small amount of gas it will pick up and pull strong like it should. Parts that came off another car that ran fine; Injectors, iacv, Tb. Im thinking my cat is clogged. Thats the only thing that hasnt been changed out "stock muffler and cat". Motor is rebuilt and has 510 miles on it. (first rebuild) lol happy it made it pass break in period. But anyways. Thanks for your help. I can post a video if needed.

 

Sorry to rain on your party but break in period is 1000 miles. You're just over halfway there, cowboy.

 

TPS may be going bad. They can develop a bad spot (like the spot where you steady cruise the most). The engine does ok until it hits that one dead spot and then the ECU thinks you are letting off the throttle and cuts fuel down, giving you the sputter. You accelerate more (or less even) and get past the dead spot and everything is as it should be. Have someone with a scope do a TPS sweep, or substitute a known good part in if you or a buddy have one laying around.

 

Yea sounds like a bad tps to me, what kind of car/engine do you have?

 

If you think so. Not that it has anything to do with the issue but there is a school of thought that strongly suggests break in should happen hard and fast.
http://www.mototuneusa.com/break_in_secrets.htm

If the TPS is suspect check it for proper voltage.

 

Oh no worries lol at least im half way there. I still see the cup half full. but the situation is ive changed the TB with a known good map and TPS. After the swap i still get the lag. Hince why i changed injectors too chasing possible leads of the problem. I have a d16z6. In a 95 civic.

 

I just read the article. I really like it. It makes sense and i think hopefully i can do this for the rest of my break in. Wish i knew this before hand. You think i will mes anything up seeing that im already pass 500?

 

SOLVED! It was the stock exhaust, cat and muffler. Installed a Yonaka full exhaust and test pipe. Hasnt lagged in two days.