Rep Power: 0

I got a 98 1.6 civic ex. It runs good cold soon as it get to normal temp it has a fit by which it cuts out like the fuel stops or the spark. I don't know what it is no codes. also I noticed it happens around 2k rpm and after it shifts to its final gear. If i let off and get back on gas it normally goes again. At times its a little slow to get moving when I pull out to go over a mountain for example. New plugs and I had the head gasket check by a garage that used fluid that changes color.. I don't know where to start with out dumping $ in parts. The trans seems to shift wierd at times like it will rev a bit when up shifting (auto trans).

 
Rep Power: 518

Got nuthin at the moment.
Might think something different if I could actually drive the car, but that ain't happening.

I'd probably want to observe live scanner data while this problem is occurring. Maybe measure backpressure during the event too.

O2 sensor has been known to cause some bucking issues, but I'm not sure if you described this here. It might be easier to spot in the datalist though, if caught in the act.

 
Rep Power: 0

The guy I bought it from said he replaced the o2 sensor in the pipe and it looks new would the one in the manifold cause this to happen? It all most seems like the fuel or spark cuts out but if you leave of and reply gas or move shifter { Automatic} to lower gear it goes. it's got me stumped I guess I just need to go to a garage and let them test it
+
thanks anyway

 
Rep Power: 0

Just wanted to update and maybe help someone else. I found it to be the upper 02 sensor in the manifold. Replaced and so far no issues with idle or stumbling! If you un plug the sensor and run it and it don't act up I 'd bet your sensor is bad.