i have a 1994 civic coupe ex 5 speed completely stock I had a no start problem a couple of years ago and resoldered the main relay under the steering wheel which fixed the problem then it would randomly die and finally I changed the distributor a couple years ago all cel lights went off and was running good until a couple of months ago the car studdered while I was doing 65 and ever since then it runs perfect from a cold start but as soon as the engine hits normal operation temp it will want to die on me at low rpm or stuffer at high rpm run like crap misfire it has half the power if that and won’t let me rev over 3000 rpms in any gear including neutral I didn’t reset the ecu when doing previous repairs because of lack of knowledge and cleaned out the egr valves also replaced the fuel filter and plugs and map sensor and but if it sits overnight the next morning it will start and run perfect until it reaches temp again.

I can run it to 8000-9000 rpm before it gets to temp.Yes it runs normal for 15-20 minutes then it will act like it wants to die the cel will come on with codes 4 and 41 the exhaust will get louder and it will have 50% power in higher gears at higher rpms and won’t go over 3000 rpms