I have a 93 civic sedan with a gsr swap in it, ive ran it fine for a year and now its starting to hesitate alot, only when the car warms up though and I've replaced my distributor, plugs n wires, adjusted my timing, new battery and starter, I think it might be my back pressure? But I have no clue, my exhaust is 4-1 and 2 1/2" exhaust with a stock 2 1/4" muffler. Anyone please help cause its buggin me! Oh and when I drive it I have to hold the rpm at 2500 to keep it moving.

 

check engine light on?

 

Yes, it only throws up o2 sensor heater, and my ecu is correct for the engine.

 

Sounds like I had same problems with my car as you do. My car ran great when engine was cold and bogged when engine was warm. Turned out to be a cracked head. Yours could be anywhere from a cracked head/block to a head gasket to a clogged cat converter or a bad coolant temp sensor. Are you loosing any coolant at all? And your o2 sensor could also be bad because of a clogged cat converter. I gutted mine and it works just fine. Cheap and easy fix.

 

Mine was a 93 civic dx coupe

 

Yeah I don't have an o2 sensor, and my coolant leaks right where it connects with the throttle body, ibjust discovered that today, and I checked my head and head gasket and its fine, no leaks or cracks, my dads a mechanic and he thinks I have an air bubble in my cooling system, but I also noticed I have an exhaust leak right wherey flex pipe is at. Idk but its frustrating me!

 

Idk if this matters but I also have my ecu jumped.

 

Update! So far I have been tinkering around and, I replaced my exhaust, and new injectors, and I made a coolant overflow tank, and I disconnected my fuel return line and my jumper wire, and the car runs great, but it still has hiccups, any extra info would help a lot but for the most part she's doing fine.

 

Inspect tps adjustment and specifications per repair manual...

 

So what exactly ended up being your problem?

 

So what ended up being the problem?

 

Is it hesitating while driving (accelerating) or just bogging up and down when the car is in neutral?