Ok here's what I know so far
B16 2nd gen swapped into 94 Civic hatch
Compression is 210psi across the board...Ecu is not throwing and codes..spark plugs are fine as well.

the down pipe is not completly connected to the rest of the exhaust, we rigged it up with a smaller pipe stuck inside just to cut down on noise until the guy could get the exhaust fixed.

so my question is could the stuttering problem be contributed to having no back pressure and getting false O2 readings?

we also drain the gas tank, put in new gas and changed the fuel fliter and injectors

at certain rpms and throttle position the engine rus fine but as soon as its under load it sounds and runs like a lawn mower....this is really starting to agrivate me because the guy keeps coming back thinking we f'd something up

thanks

Chris

 

UP

 

No, backpressure effects torque output/location by way of exhaust gas movement in feet/per second, it doesnt make your car run like ***.

Its porbably the 02 sensor. Sometimes they dont throw codes. I have no clue why. Unhook it, see if anything changes. Check your TPS and your MAP, if nothing else works, run over every vacuum line to make sure they are correct.